feat(cpg): the hook half — CVE-2022-25148 found across an add_filter/apply_filters edge

The last of the three WordPress flaw classes 5.8 measured as missed. The
value crosses a registry inside WordPress core:

    add_filter('wp_statistics_current_page', array($this, 'set_current_page'));
    return apply_filters('wp_statistics_current_page', $current_page);

php2cpg drops the callback argument entirely -- the CPG holds
`add_filter("wp_statistics_current_page", )` -- so the edge cannot come from
the graph at any price. It comes from the source text instead, where both ends
are literals, via `mapping.php_hook_callbacks`.

                 vulnerable                              fixed
  wpstatistics   3 entailed, incl. pages.php:225:record  2, that one absent
  mwwpform       1 ($this->attachments)                  0
  pmpro          18, incl. CVE at :936                   1
  VAmPI          4                                       unchanged

The correctly-prepared sibling query one line below the CVE is not flagged on
either side.

Four things this cost, each measured rather than guessed:

  * Half one must be asked per ARRAY KEY, not per callback. "Does an
    unsanitized value reach this callback's return" is TRUE on both sides: the
    fix escapes `type` and `id` and leaves `search_query` alone. A
    callback-level answer flags the fixed side as readily as the vulnerable
    one, which is a leak, not a detection. The key is a literal at both ends,
    so it joins the way the hook name and the field name do -- the same idea
    for the third time.

  * The sanitizer test had to stop crediting a sibling's cleansing. The
    vulnerable query is ONE concatenation holding both `esc_sql($page_uri)`
    and the injectable `{$current_page['id']}`, so asking whether a
    sanitizer's name appears in a path element's text marked the whole flow
    sanitized. An element must now BE the cleansing -- a call to it, or its
    name as a string literal, which keeps `array_map('esc_sql', ...)` working.

  * Hook seeds are repository-wide where field seeds are file-scoped. A hook
    registry is global by construction: the callback is in one file and its
    `apply_filters` in another. The query returned nothing until those two
    scopes were separated.

  * `sourceKind` had to be REPORTED, not inferred. By the time a row reaches
    Python a hook source reads as `$current_page["id"]` and a parameter as
    `$args`, and `_usable_flows` discards parameter flows whenever a modelled
    one is present -- so seven sanitized `$_SERVER["REQUEST_URI"]` flows
    displaced the CVE between the query and the verdict. That preference then
    had to move PER SINK SITE: applied across a region it decides one site's
    question with another site's evidence, and PMPro's CVE at :936 vanished
    from a region still reporting fifteen other findings.

`verdict` now delegates to `verdicts` rather than running its own selection
over the union, because two copies of "which flow decides" is exactly the
duplication this module has been bitten by before -- and had been again: the
per-site preference did not reach the single-verdict path, so the two entry
points disagreed about the same rows.

841 tests pass; gates byte-identical; VAmPI unchanged.

Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>
Claude-Session: https://claude.ai/code/session_01T7XD7x5KonMdmGRkp63EQG

.kiro/specs/contributor-scan/tasks.md

@@ -590,7 +590,7 @@
   - _Requirements: 4.2, 4.3, 9.1_
   - _Depends: 5.7_
 
-- [~] 5.11 Two-stage taint with a link table — the detection strategy for both structural misses
+- [x] 5.11 Two-stage taint with a link table — the detection strategy for both structural misses
   - "Structurally impossible" is a verdict, not a plan, and both PHP structural misses turn out to be the
     SAME shape: two halves of a path, joined by a key that is a literal in the source text.
 
@@ -654,8 +654,40 @@
       analysis twice costs more than skipping path reconstruction saves.
     - Memoizing per **field** rather than per file took it to 97s, because only fields some region actually
       reads are worth the flow query. Roughly 1.6x the pre-field cost for that class.
-  - Still open: the hook half, and the one finding that survives on PMPro's fixed side
-    (`saveOrder:1469 <- $this->timestamp`).
+  - **Hook half done 2026-09-09, and CVE-2022-25148 is found.**
+
+    | | vulnerable | fixed |
+    |---|---|---|
+    | `wpstatistics` | 3 entailed, incl. `class-wp-statistics-pages.php:225:record` | 2 entailed, that one absent |
+    | `mwwpform` | 1 (`$this->attachments`) | 0 |
+    | `pmpro` | 18, incl. CVE at `:936` | 1 |
+    | VAmPI | 4 | unchanged |
+
+    The link table is `mapping.php_hook_callbacks`, read from the source text -- php2cpg drops a
+    registration's callback argument, so the CPG holds `add_filter("wp_statistics_current_page", )` and the
+    edge cannot come from the graph at any price.
+  - Four things this cost, each a measurement rather than a guess:
+    - **Half one must be asked per ARRAY KEY, not per callback.** "Does an unsanitized value reach this
+      callback's return" is TRUE on both sides: the fix escapes `type` and `id` and leaves `search_query`
+      alone. A callback-level answer flags the fixed side as readily as the vulnerable one, which is a leak.
+      The key is a literal at both ends -- `"id"` in the callback, `['id']` at the sink -- so it joins the
+      same way the hook name and the field name do. Third use of the one idea.
+    - **The sanitizer test had to stop crediting a sibling's cleansing.** WP Statistics' query is one
+      concatenation holding `esc_sql($page_uri)` AND the injectable `{$current_page['id']}`; asking whether a
+      sanitizer's name appears in a path element's text marked the whole flow sanitized. An element must now
+      BE the cleansing -- a call to it, or its name as a string literal, which keeps `array_map('esc_sql', ...)`
+      working.
+    - **Hook seeds are repository-wide where field seeds are file-scoped.** A hook registry is global by
+      construction: `set_current_page` is in one file and its `apply_filters` in another. The query returned
+      nothing at all until those two scopes were separated.
+    - **`sourceKind` had to be reported, not inferred.** By the time a row reaches Python a hook source reads
+      as `$current_page["id"]` and a parameter as `$args`. `_usable_flows` discards parameter flows whenever
+      a modelled one is present, so seven sanitized `$_SERVER["REQUEST_URI"]` flows displaced the CVE. And
+      that preference had to move PER SINK SITE: applied across a region it decided one site with another
+      site's evidence, and PMPro's CVE at :936 vanished from a region still reporting fifteen findings.
+  - Still open: array-key sensitivity is only modelled where the callback builds its result by key
+    assignment; the one finding surviving on PMPro's fixed side (`saveOrder:1469 <- $this->timestamp`); and
+    `verdict` now delegates to `verdicts`, so the two can no longer disagree.
   - _Requirements: 4.4, 6.1, 8.1, 9.1_
   - _Depends: 5.8_
 

benchmarks/repos/README.md

@@ -70,7 +70,7 @@ text, and each measured against its own fixed commit.
 |---|---|---|---|---|
 | Unauthenticated injection, sink in the function that receives the value | `pmpro`, CVE-2023-23488 | entailed at `class.memberorder.php:936:getMemberOrderByCode`, sourced from `$code` | absent | **found**, and the pair separates |
 | Arbitrary file operation | `mwwpform`, CVE-2023-6559 | entailed at `class.mail.php:259:_delete_files` | absent | **found**, and the pair separates |
-| Unauthenticated injection, value crosses a WordPress hook | `wpstatistics`, CVE-2022-25148 | not reported | not reported | **missed**, structurally |
+| Unauthenticated injection, value crosses a WordPress hook | `wpstatistics`, CVE-2022-25148 | entailed at `class-wp-statistics-pages.php:225:record` | absent | **found**, and the pair separates |
 | Missing capability check | — | — | — | **cannot be asked**: PHP has no obligation facts |
 | Unescaped output | — | — | — | **cannot be trusted**: the sanitizer list is flat |
 
@@ -135,7 +135,17 @@ not merely its reachability. Asking only "does a source reach this assignment" m
 fixed side went from 1 finding to 13 before that clause existed, which is the pair no longer separating at
 all. It costs about 1.6× on the taint query for that class (62s → 97s), memoised per field.
 
-The hook half is the same machinery against a different key, and is not written yet.
+**The hook half is implemented too, and CVE-2022-25148 is found**: `class-wp-statistics-pages.php:225:record`
+on the vulnerable side, absent on the fixed side, with the correctly-`prepare`d sibling query one line below
+it not flagged on either. The link table is read from the source text, because php2cpg drops a registration's
+callback argument entirely -- the CPG holds `add_filter("wp_statistics_current_page", )`, so the edge cannot
+come from the graph at any price.
+
+The half that mattered was asking per ARRAY KEY rather than per callback. "Does an unsanitized value reach
+this callback's return" is true on *both* sides, because the fix escapes `type` and `id` and leaves
+`search_query` alone; a callback-level answer flags the fix as readily as the bug. The key is a literal at
+both ends — `"id"` where the callback writes it, `['id']` where the sink reads it — so it joins the same way
+the hook name and the field name do. That is the same idea for the third time.
 
 What the engine reports on that plugin instead is two other sites — `getTop:406` and `TotalCount:443` — the
 same weakness class at the wrong lines, identical on both sides, so the pair does not separate. They are not

src/openultrasast/cpg/queries/taint.sc

@@ -48,6 +48,7 @@
     callDepth: String = "0",
     boundedSinks: String = "",
     parameterSources: String = "false",
+    hookCallbacks: String = "",
     requests: String = "",
     requestsFile: String = ""
 ) = {
@@ -66,6 +67,7 @@
       sourcesS: String,
       sinksS: String,
       sanitizersS: String,
+      hookCallbacksS: String,
       functionS: String,
       paramSrc: String,
       fileS: String,
@@ -183,6 +185,21 @@
     else if (function.isEmpty) cpg.method.parameter.filterNot(_.name == "this").iterator
     else cpg.method.nameExact(function).parameter.filterNot(_.name == "this").iterator
 
+  // The region this request is about, as a predicate on the method. Named rather than inlined because the
+  // field sources have to be scoped to exactly the same place as the sinks, and a second copy of these
+  // three branches is precisely the drift this file has been bitten by before.
+  def inScope(m: io.shiftleft.codepropertygraph.generated.nodes.Method): Boolean =
+    if (function.isEmpty) {
+      // A region with no enclosing function: the file IS the scope.
+      fileS.isEmpty || m.filename.endsWith(fileS)
+    } else if (depth > 0) {
+      // Following the call graph means leaving the region's file on purpose, so the file filter would
+      // contradict the point. The reachable set is the scope, and the row reports where the sink landed.
+      nestedInLabeled(m) || reachableMethods.contains(m.fullName)
+    } else {
+      (fileS.isEmpty || m.filename.endsWith(fileS)) && nestedInLabeled(m)
+    }
+
   // ---- the field half of the two-stage join (task 5.11) ---------------------------------------------
   //
   // `_delete_files()` takes no parameters at all. Its attacker-controlled path arrives as a FIELD, written
@@ -260,12 +277,172 @@
       }
     )
 
-  def fieldSourceNodes = {
-    val reads = cpg.call.nameExact(FIELD_ACCESS).filter(c => inScope(c.method)).l
-    if (reads.isEmpty) Iterator.empty else reads.filter(r => fieldIsTainted(fileS, r.code.trim)).iterator
+  // A read of a MEMBER of a tainted object is tainted too. WP Statistics assigns the whole request to
+  // `$this->rest_hits` in one method and reads `$this->rest_hits->current_page_id` in another, so an exact
+  // code match sees two unrelated strings where the source text says one is inside the other. Every prefix
+  // that ends on a `->` boundary is checked, left to right.
+  def taintedPrefixes(code: String, fileName: String): Boolean = {
+    val parts = code.split("->").map(_.trim).filter(_.nonEmpty)
+    if (parts.length < 2) false
+    else (2 to parts.length).exists(n => fieldIsTainted(fileName, parts.take(n).mkString("->")))
   }
 
-  def sourceNodes = frameworkSources.l.iterator ++ parameterNodes ++ fieldSourceNodes
+  def fieldSourceNodes = {
+    val reads = cpg.call.nameExact(FIELD_ACCESS).filter(c => inScope(c.method)).l
+    if (reads.isEmpty) Iterator.empty else reads.filter(r => taintedPrefixes(r.code.trim, fileS)).iterator
+  }
+
+  // ---- the hook half of the two-stage join (task 5.11) ----------------------------------------------
+  //
+  // WP Statistics' CVE-2022-25148 has a modelled source, a modelled sink and `esc_sql` as its fix, and is
+  // invisible on both sides, because the only thing joining the two files is
+  //
+  //     add_filter('wp_statistics_current_page', array($this, 'set_current_page'));   // hits.php:43
+  //     return apply_filters('wp_statistics_current_page', $current_page);            // pages.php:105
+  //
+  // Both ends name the callback with a STRING, and php2cpg drops the callback argument entirely -- the CPG
+  // literally holds `add_filter("wp_statistics_current_page", )`. So the link CANNOT come from the graph at
+  // any price, and it arrives instead as `hookCallbacks`, read out of the source text by
+  // `mapping.php_hook_callbacks` where both ends are literals.
+  //
+  // The rule: an `apply_filters('H', ...)` call is a SOURCE when some callback registered for H returns
+  // data that an unsanitized flow reached. That is the same question as the field half, against a different
+  // key.
+  val HOOK_APPLY = Set("apply_filters", "apply_filters_ref_array", "do_action", "do_action_ref_array")
+
+  val hookTable: Map[String, List[String]] =
+    hookCallbacksS
+      .split(";")
+      .map(_.trim)
+      .filter(_.nonEmpty)
+      .flatMap { entry =>
+        val at = entry.indexOf(':')
+        if (at <= 0 || at == entry.length - 1) None else Some(entry.substring(0, at) -> entry.substring(at + 1))
+      }
+      .groupBy(_._1)
+      .map { case (hook, pairs) => hook -> pairs.map(_._2).toList }
+
+  def unquote(raw: String): String = {
+    val t = raw.trim
+    if (t.length >= 2 && ((t.head == '"' && t.last == '"') || (t.head == '\'' && t.last == '\''))) t.substring(1, t.length - 1) else t
+  }
+
+  // Half one's seeds are STRICTER than the field half's, and deliberately. A filter callback's own parameter
+  // is the value being filtered, not request data, and the receiver is the object -- counting either makes
+  // every registered callback "return tainted" and the join degenerates into the complete graph this design
+  // exists to refuse. Only a real framework source, or a field already shown to hold one, counts.
+  //
+  // They are also NOT scoped to the requesting file, which the field half is. A hook registry is global by
+  // construction: the whole point of the edge is that `set_current_page` lives in one file and the
+  // `apply_filters` that calls it lives in another. Scoping these seeds the way the field half scopes its
+  // own defeats exactly the join being built, and the query returned nothing until this was separated.
+  val hookSeedsByFile = scala.collection.mutable.Map.empty[String, List[io.shiftleft.codepropertygraph.generated.nodes.CfgNode]]
+
+  def hookSeedsIn(fileName: String) =
+    hookSeedsByFile.getOrElseUpdate(
+      fileName, {
+        val methods = methodsIn(fileName)
+        val framework: List[io.shiftleft.codepropertygraph.generated.nodes.CfgNode] =
+          methods.flatMap(_.ast.isCall.filter(c => sourcePatterns.exists(p => c.code.contains(p))).l)
+        val fields: List[io.shiftleft.codepropertygraph.generated.nodes.CfgNode] =
+          methods.flatMap(_.ast.isCall.nameExact(FIELD_ACCESS).l).filter(r => taintedPrefixes(r.code.trim, fileName))
+        framework ++ fields
+      }
+    )
+
+  // Half one is asked PER ARRAY KEY, not per callback, and that distinction is the whole result.
+  //
+  // "Does an unsanitized value reach this callback's return" is true on BOTH sides of the WP Statistics
+  // pair, because the fix escapes two of the three members and leaves the third alone:
+  //
+  //     vulnerable   $tmp["id"] = $this->rest_hits->current_page_id
+  //     fixed        $tmp["id"] = esc_sql($this->rest_hits->current_page_id)
+  //     both         $tmp["search_query"] = ... unescaped, and harmless where it is used
+  //
+  // A callback-level answer flags the fixed side exactly as readily as the vulnerable one, which is a leak
+  // and not a detection. The key is a literal at both ends -- written `"id"` in the callback and `['id']`
+  // at the sink -- so it joins the same way the hook name and the field name do. Third use of one idea.
+  val INDEX_ACCESS = "<operator>.indexAccess"
+  val hookKeysMemo = scala.collection.mutable.Map.empty[(String, String), Set[String]]
+
+  def keyOf(access: io.shiftleft.codepropertygraph.generated.nodes.Call): String =
+    access.argument.l.lift(1).map(a => unquote(a.code)).getOrElse("")
+
+  def taintedKeysOf(fileName: String, callback: String): Set[String] =
+    hookKeysMemo.getOrElseUpdate(
+      (fileName, callback), {
+        val seeds = hookSeedsIn(fileName)
+        if (seeds.isEmpty) Set.empty[String]
+        else
+          cpg.method
+            .nameExact(callback)
+            .ast
+            .isCall
+            .nameExact(ASSIGNMENT)
+            .l
+            .flatMap { assignment =>
+              val args = assignment.argument.l
+              if (args.size < 2) None
+              else
+                args.head match {
+                  case target: io.shiftleft.codepropertygraph.generated.nodes.Call if target.name == INDEX_ACCESS =>
+                    val key = keyOf(target)
+                    if (key.isEmpty) None
+                    else if (args(1).start.reachableByFlows(seeds.iterator).l.exists(f => !f.elements.l.exists(sanitizesHere)))
+                      Some(key)
+                    else None
+                  case _ => None
+                }
+            }
+            .toSet
+      }
+    )
+
+  def hookSourceNodes =
+    if (hookTable.isEmpty) Iterator.empty
+    else {
+      val applies = cpg.call.filter(c => HOOK_APPLY.contains(c.name)).filter(c => inScope(c.method)).l
+      if (applies.isEmpty) Iterator.empty
+      else {
+        val keys = applies.flatMap { call =>
+          val hook = call.argument.l.headOption.map(a => unquote(a.code)).getOrElse("")
+          hookTable.getOrElse(hook, Nil).flatMap(cb => taintedKeysOf("", cb))
+        }.toSet
+        if (keys.isEmpty) Iterator.empty
+        else
+          cpg.call
+            .nameExact(INDEX_ACCESS)
+            .filter(c => inScope(c.method))
+            .l
+            .filter(access => keys.contains(keyOf(access)))
+            // ...and actually derived from the filtered value, not merely sharing a key name with it.
+            .filter(access => access.start.reachableBy(applies.iterator).nonEmpty)
+            .iterator
+      }
+    }
+
+  def sourceNodes = frameworkSources.l.iterator ++ parameterNodes ++ fieldSourceNodes ++ hookSourceNodes
+
+  // WHICH KIND of source a flow started from, reported per row so the driver can tell them apart.
+  //
+  // It has to be reported rather than guessed, because by the time a row reaches Python a hook source reads
+  // as `$current_page["id"]` and a parameter reads as `$args` -- two identifiers, indistinguishable. The
+  // driver treats parameter-sourced flows as a FALLBACK it discards whenever a real modelled source is also
+  // present, which is right for parameters and wrong for these: on WP Statistics, seven sanitized
+  // `$_SERVER["REQUEST_URI"]` flows displaced the unsanitized hook flow carrying CVE-2022-25148, and the
+  // finding disappeared between the query and the verdict.
+  lazy val frameworkIds = frameworkSources.l.map(_.id).toSet
+  lazy val fieldIds     = fieldSourceNodes.map(_.id).toSet
+  lazy val hookIds      = hookSourceNodes.map(_.id).toSet
+
+  def sourceKindOf(head: Option[io.shiftleft.codepropertygraph.generated.nodes.AstNode]): String =
+    head match {
+      case Some(node) if frameworkIds.contains(node.id) => "framework"
+      case Some(node) if hookIds.contains(node.id)      => "hook"
+      case Some(node) if fieldIds.contains(node.id)     => "field"
+      case Some(_)                                      => "parameter"
+      case None                                         => ""
+    }
 
   // Whether there is anything to trace from at all. Asking `reachableByFlows` with an empty source list is
   // not merely wasted work: Joern answers it by logging "Attempting to determine flows from empty list of
@@ -287,19 +464,30 @@
   def sinkMatches(c: io.shiftleft.codepropertygraph.generated.nodes.Call, n: String): Boolean =
     c.name == n || c.code.startsWith(n + "(") || mentionsToken(c.code, List(n)) || mentionsToken(c.methodFullName, List(n))
 
-  // The region this request is about, as a predicate on the method. Named rather than inlined because the
-  // field sources have to be scoped to exactly the same place as the sinks, and a second copy of these
-  // three branches is precisely the drift this file has been bitten by before.
-  def inScope(m: io.shiftleft.codepropertygraph.generated.nodes.Method): Boolean =
-    if (function.isEmpty) {
-      // A region with no enclosing function: the file IS the scope.
-      fileS.isEmpty || m.filename.endsWith(fileS)
-    } else if (depth > 0) {
-      // Following the call graph means leaving the region's file on purpose, so the file filter would
-      // contradict the point. The reachable set is the scope, and the row reports where the sink landed.
-      nestedInLabeled(m) || reachableMethods.contains(m.fullName)
-    } else {
-      (fileS.isEmpty || m.filename.endsWith(fileS)) && nestedInLabeled(m)
+  // Does THIS path element cleanse the value flowing through it?
+  //
+  // The old test asked whether a sanitizer's name appeared anywhere in the element's source text, and that
+  // is wrong on exactly the shape WordPress writes. WP Statistics' vulnerable query is one concatenation:
+  //
+  //     "... " . (array_key_exists(...) ? "AND `uri` = '" . esc_sql($page_uri) . "'" : "")
+  //             . "AND `id` = {$current_page['id']}"
+  //
+  // `esc_sql` cleanses `$page_uri`. It does nothing whatsoever for `$current_page['id']`, which is the
+  // injectable value and CVE-2022-25148 -- but both live in one expression, so the concatenation node's
+  // code mentions `esc_sql` and the whole flow read as sanitized. A sibling's cleansing was being credited
+  // to its neighbour.
+  //
+  // So the element must BE the cleansing, not merely contain a mention of one:
+  //   * a call to the sanitizer -- by node name, or by its code opening with `name(`;
+  //   * the sanitizer named as a string literal, which is how `array_map('esc_sql', $status)` applies it and
+  //     is a form PMPro actually writes.
+  def sanitizesHere(node: io.shiftleft.codepropertygraph.generated.nodes.AstNode): Boolean = {
+    val code = node.code
+    val byName = node match {
+      case call: io.shiftleft.codepropertygraph.generated.nodes.Call => sanitizerNames.exists(n => call.name == n)
+      case _                                                        => false
+    }
+    byName || sanitizerNames.exists(n => code.startsWith(n + "(") || code.contains("'" + n + "'") || code.contains("\"" + n + "\""))
   }
 
   def sinkCalls = cpg.call.filter(c => sinkNames.exists(n => sinkMatches(c, n))).filter(c => inScope(c.method))
@@ -344,9 +532,11 @@
 
     flows.map { flow =>
       val elements = flow.elements.map(_.code).l
-      val sanitized = sanitizerNames.nonEmpty && elements.exists(code => mentionsToken(code, sanitizerNames))
+      val sanitized = sanitizerNames.nonEmpty && flow.elements.l.exists(node => sanitizesHere(node))
+      val sourceKind = sourceKindOf(flow.elements.l.headOption)
       ujson.Obj(
         "sink"            -> sink.code.take(200),
+        "sourceKind"      -> sourceKind,
         "sinkLine"        -> sink.lineNumber.getOrElse(-1).toString,
         "sinkMethod"      -> sink.method.name,
         // Where the sink actually is. With callDepth > 0 that need not be the region's own file, and a
@@ -378,6 +568,7 @@
           field("sources"),
           field("sinks"),
           field("sanitizers"),
+          field("hookCallbacks"),
           field("function"),
           paramSrc,
           field("file"),
@@ -395,7 +586,7 @@
     println(ujson.write(ujson.Obj.from(answers.toSeq :+ ("__census__" -> census))))
   } else {
     println(
-      ujson.write(ujson.Arr(rowsFor(sources, sinks, sanitizers, function, parameterSources, file, callDepth, boundedSinks): _*))
+      ujson.write(ujson.Arr(rowsFor(sources, sinks, sanitizers, hookCallbacks, function, parameterSources, file, callDepth, boundedSinks): _*))
     )
   }
   println("---OUSAST-CPG-END---")

src/openultrasast/mapping.py

@@ -117,6 +117,36 @@ def analyze_entry_points(root: Path, targets: list[FileTarget]) -> list[EntryPoi
     return sorted(records, key=lambda item: (item.path, item.line is None, item.line or 0, item.name))
 
 
+def php_hook_callbacks(root: Path, targets: list[FileTarget]) -> dict[str, tuple[str, ...]]:
+    """WordPress's hook registry, read out of the source text because the graph does not carry it.
+
+    `php2cpg` 4.0.623 drops the callback argument of a registration entirely. What the CPG holds is
+
+        add_filter("wp_statistics_current_page", )
+
+    with an empty second argument, so the link between a hook and its handler cannot be recovered from the
+    graph at any price. It can be recovered from the source, where both ends are string literals -- and that
+    is the same place, and the same regex, the entry-point mapper already reads them from.
+
+    This is the link table for the hook half of the two-stage join (task 5.11). It is deliberately a plain
+    name-to-names mapping with no inference in it: a hook whose name is computed (`"save_post_" . $type`)
+    simply does not appear, rather than being guessed at.
+    """
+    table: dict[str, set[str]] = {}
+    for target in targets:
+        if target.language != "php":
+            continue
+        try:
+            text = (root / target.path).read_text(errors="ignore")
+        except OSError:
+            continue
+        for match in _PHP_REGISTRATION.finditer(text):
+            handler = match.group("handler") or match.group("method")
+            if handler:
+                table.setdefault(match.group("hook"), set()).add(handler)
+    return {hook: tuple(sorted(names)) for hook, names in sorted(table.items())}
+
+
 def attach_reachability_hints(targets: list[FileTarget], entry_points: list[EntryPointRecord]) -> list[FileTarget]:
     hints_by_path: dict[str, list[dict[str, object]]] = {}
     for entry_point in entry_points:

src/openultrasast/model/scan.py

@@ -146,6 +146,12 @@ def scan_repository(
     # spent in belongs to whoever holds the budget.
     ordered_regions = sorted(regions, key=lambda r: (not r.shipped, -r.rank, r.path, r.function or ""))
 
+    # The hook link table, built once for the whole scan. It is a property of the repository rather than of
+    # any region, and it is read from the source text because the graph does not carry it: php2cpg drops a
+    # registration's callback argument, so `add_filter("hook", array($this, "m"))` reaches the CPG as
+    # `add_filter("hook", )`. See `mapping.php_hook_callbacks`.
+    hooks = _hook_callbacks(root, regions)
+
     # Phase 1: collect the whole scan's questions, for at most `max_regions` regions. Nothing is asked yet.
     work: list[tuple[str, ScanRegion, ArbiterSpec]] = []
     for region in ordered_regions[: limits.max_regions]:
@@ -162,7 +168,7 @@ def scan_repository(
     per_kind: dict[str, float] = {}
     census_reported = False
     query_started = time.monotonic()
-    for kind, requests in _grouped(work).items():
+    for kind, requests in _grouped(work, hook_callbacks=hooks).items():
         kind_started = time.monotonic()
         batch = getattr(cpg, "run_batch", None)
         if callable(batch):
@@ -276,7 +282,9 @@ def _prefetched(rows: list[object]):  # type: ignore[no-untyped-def]
     return run
 
 
-def _grouped(work: Sequence[tuple[str, ScanRegion, ArbiterSpec]]) -> dict[str, dict[str, Mapping[str, object]]]:
+def _grouped(
+    work: Sequence[tuple[str, ScanRegion, ArbiterSpec]], *, hook_callbacks: str = ""
+) -> dict[str, dict[str, Mapping[str, object]]]:
     """The work, keyed by query kind, with each request built by the arbiter's OWN parameter function.
 
     Building the parameters here instead would be a second copy that drifts from the arbiter's -- the exact
@@ -299,12 +307,32 @@ def _grouped(work: Sequence[tuple[str, ScanRegion, ArbiterSpec]]) -> dict[str, d
                     file=region.path,
                     parameter_sources=entry,
                     call_depth=ENTRY_POINT_CALL_DEPTH if entry else 0,
+                    hook_callbacks=hook_callbacks,
                 ),
             )
         grouped.setdefault(kind, {})[rid] = params
     return grouped
 
 
+def _hook_callbacks(root: Path, regions: Sequence[ScanRegion]) -> str:
+    """``hook:callback;hook:callback`` for the PHP files this scan is about, or ``""``.
+
+    Rendered here rather than in the query because a CPGQL parameter is a string, and rendered from the
+    regions rather than by walking the tree because the regions already name every file in scope.
+    """
+    paths = sorted({region.path for region in regions if region.language == "php" and region.path})
+    if not paths:
+        return ""
+    from ..mapping import php_hook_callbacks
+    from ..preprocess import FileTarget
+
+    targets = [
+        FileTarget(path=path, absolute_path=str(root / path), language="php", loc=0, tags=[], has_fuzz_entry_point=False) for path in paths
+    ]
+    table = php_hook_callbacks(root, targets)
+    return ";".join(f"{hook}:{name}" for hook, names in table.items() for name in names)
+
+
 def _is_entry_point(region: ScanRegion) -> bool:
     """Is this region a place untrusted input actually enters?
 

src/openultrasast/model/taint.py

@@ -20,7 +20,13 @@ from .specs import TaintSpec
 
 
 def request_params(
-    spec: TaintSpec, *, function: str = "", file: str = "", parameter_sources: bool = False, call_depth: int = 0
+    spec: TaintSpec,
+    *,
+    function: str = "",
+    file: str = "",
+    parameter_sources: bool = False,
+    call_depth: int = 0,
+    hook_callbacks: str = "",
 ) -> dict[str, object]:
     """The query parameters this arbiter sends. Shared with the batcher so there is one definition, not two.
 
@@ -41,6 +47,10 @@ def request_params(
         "parameterSources": "true" if parameter_sources else "false",
         "callDepth": str(call_depth),
         "boundedSinks": spec.bounded_sinks,
+        # The hook link table, `hook:callback;hook:callback`. Read out of the source text rather than the
+        # graph, because php2cpg drops a registration's callback argument entirely -- see
+        # `mapping.php_hook_callbacks`. Empty for every language that does not register handlers by string.
+        "hookCallbacks": hook_callbacks,
     }
 
 
@@ -59,9 +69,11 @@ def verdict(
     function-local question; above zero is what lets a handler's parameter reach a sink in another module,
     which is the shape VAmPI's SQL injection has and the shape a function-scoped question cannot see.
     """
-    considered = _usable_flows(cpg, spec, function=function, file=file, parameter_sources=parameter_sources, call_depth=call_depth)
-    if not considered:
-        return None
+    # The strongest of the per-site verdicts, which is what this always meant. It used to run its own
+    # selection over the union of flows, and two copies of "which flow decides" is the duplication this
+    # module has been bitten by before: the per-site preference added to `verdicts` did not reach here, so
+    # the two entry points disagreed about the same rows.
+    #
     # A flow the graph cannot see a discharge for is the finding; a sanitized or BOUNDED one is a question.
     # libpng bounds `strcpy(outname+len, ".png")` with `(len = strlen(inname)) > 250` against a char[256],
     # and entailing it is a claim the code contradicts. But the bound reaches the sink through an `error`
@@ -69,10 +81,8 @@ def verdict(
     # bound is no proof of safety in any case, off-by-one being the classic way they fail. Corroborated is
     # the honest rung: the model cannot assert this, so the judge is asked instead of the site being
     # silenced.
-    open_flows = [flow for flow in considered if not flow["sanitized"] and not flow["bounded"]]
-    # Deterministic by construction: a total order, then take the first. Nothing depends on engine ordering.
-    chosen = min(open_flows or considered, key=lambda flow: _rank(flow, spec))
-    return _verdict_for(chosen, spec)
+    answers = verdicts(cpg, spec, function=function, file=file, parameter_sources=parameter_sources, call_depth=call_depth)
+    return answers[0] if answers else None
 
 
 def _usable_flows(
@@ -100,9 +110,7 @@ def _usable_flows(
         "taint",
         request_params(spec, function=function, file=file, parameter_sources=parameter_sources, call_depth=call_depth),
     )
-    flows = [flow for flow in _flows(rows, function=function) if not _has_safe_shape(flow, spec)]
-    modelled = [flow for flow in flows if _from_modelled_source(flow, spec)]
-    return modelled or flows
+    return [flow for flow in _flows(rows, function=function) if not _has_safe_shape(flow, spec)]
 
 
 def verdicts(
@@ -134,8 +142,13 @@ def verdicts(
 
     chosen: list[Mapping[str, object]] = []
     for site_flows in by_site.values():
-        open_flows = [flow for flow in site_flows if not flow["sanitized"] and not flow["bounded"]]
-        chosen.append(min(open_flows or site_flows, key=lambda flow: _rank(flow, spec)))
+        # Parameter sources are a FALLBACK, never an override, and that preference is PER SINK SITE. Applied
+        # across the whole region it decides one site's question with another site's evidence: on Paid
+        # Memberships Pro, field-sourced flows at lines 671 and 705 displaced the parameter-sourced flow at
+        # 936, and CVE-2023-23488 vanished from a region that still reported fifteen other findings.
+        preferred = [flow for flow in site_flows if _from_modelled_source(flow, spec)] or list(site_flows)
+        open_flows = [flow for flow in preferred if not flow["sanitized"] and not flow["bounded"]]
+        chosen.append(min(open_flows or preferred, key=lambda flow: _rank(flow, spec)))
     # Same total order the single-verdict path uses, so `verdicts(...)[0] == verdict(...)`.
     chosen.sort(key=lambda flow: (bool(flow["sanitized"]) or bool(flow["bounded"]), _rank(flow, spec)))
     return [_verdict_for(flow, spec) for flow in chosen]
@@ -170,6 +183,7 @@ def _flows(rows: object, *, function: str) -> list[dict[str, object]]:
                 "bound": str(row.get("bound", "")),
                 "source": str(row.get("source", "")),
                 "sanitized": bool(row.get("sanitized", False)),
+                "sourceKind": str(row.get("sourceKind", "")),
                 "length": _as_int(row.get("length")),
             }
         )
@@ -215,8 +229,25 @@ def _in_scope(row: Mapping[str, object], function: str) -> bool:
     return str(row.get("sinkMethod", "")) == function
 
 
+# A source the model VOUCHES for, as opposed to a bare captured parameter. The two-stage joins produce the
+# first kind without producing a superglobal: a hook source reads as `$current_page["id"]` and a field source
+# as `$this->attachments`, neither of which matches a source pattern, yet both were established by a flow the
+# query resolved from a real one.
+_MODELLED_KINDS = frozenset({"framework", "field", "hook"})
+
+
 def _from_modelled_source(flow: Mapping[str, object], spec: TaintSpec) -> bool:
-    """Does this flow start at something the source model names, rather than a bare captured parameter?"""
+    """Does this flow start at something the source model names, rather than a bare captured parameter?
+
+    `sourceKind` is the engine's own answer and wins when present. Before it existed this was decided by
+    matching the source's TEXT against the source patterns, which cannot see the difference between a hook
+    source and a parameter -- both are just identifiers by then. On WP Statistics that cost the CVE: seven
+    sanitized `$_SERVER["REQUEST_URI"]` flows counted as modelled, the unsanitized hook flow did not, and
+    `modelled or flows` in `_usable_flows` discarded the finding between the query and the verdict.
+    """
+    kind = str(flow.get("sourceKind", ""))
+    if kind:
+        return kind in _MODELLED_KINDS
     source = str(flow["source"])
     return any(pattern in source for pattern in spec.sources)