GHSA-pjhx-3c3w-9v23
MEDIUMGHSA-pjhx-3c3w-9v23 is a medium-severity (CVSS 5.9) CWE-524 vulnerability in api-platform/core. O3 Security confirms whether GHSA-pjhx-3c3w-9v23 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
API Platform Core vulnerable to cross-user attribute leak in JSON:API and HAL item normalizers due to missing isCacheKeySafe gate
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for GHSA-pjhx-3c3w-9v23.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
GHSA-pjhx-3c3w-9v23 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 370,894 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
api-platform/core🐘api-platform/core🐘api-platform/core🐘api-platform/json-api🐘api-platform/json-api🐘api-platform/json-api🐘api-platform/hal🐘api-platform/hal+1 moreReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.
Description
Impact
#[ApiProperty(security: ...)] is evaluated per request to decide whether a property is exposed. The componentsCache arrays in ApiPlatform\JsonApi\Serializer\ItemNormalizer and ApiPlatform\Hal\Serializer\ItemNormalizer are keyed on $context['cache_key'], which is set unconditionally before delegating to the parent normalizer. The component structure (attributes, relationships, links) computed for one request can therefore be reused for a subsequent request whose user has a different set of accessible properties. A user with lower privileges may end up seeing the structure of properties that the security predicate would otherwise have hidden for them.
This is the same vulnerability class as GHSA-428q-q3vv-3fq3 / CVE-2025-31485, which fixed only the GraphQL ItemNormalizer. The JSON:API and HAL paths were not addressed at the time.
Exploitation conditions
Exploitation requires all of the following to coincide:
- The application exposes a resource via the JSON:API and/or HAL formats.
- At least one property of that resource uses
#[ApiProperty(security: ...)]with a predicate whose result depends on the current user (or on per-request state). - A request from a user for whom the predicate evaluates to
truepopulatescomponentsCachebefore a request from a user for whom the predicate evaluates tofalse, within the lifetime of the same PHP process. - The deployment uses a long-running PHP runtime that keeps the normalizer instance alive across requests (FrankenPHP worker mode, RoadRunner, Swoole, ReactPHP, etc.). With classic
php-fpmworkers the cache only survives the duration of a single request, which makes the issue much harder to observe in practice.
Patches
- 4.1.29
- 4.2.25
- 4.3.8
All three branches receive patched releases of api-platform/core, api-platform/json-api, and api-platform/hal.
Workarounds
Override the JSON:API and HAL ItemNormalizer services to gate $context['cache_key'] with a resource-class security check, or avoid #[ApiProperty(security: ...)] on resources served as JSON:API or HAL until the patch is applied. Pinning the deployment to classic php-fpm workers also limits exposure since the cache does not survive across requests.
Credits
- Tillmann Baumgart (@tillmon) — originally identified the broader cache-key gap and proposed moving
isCacheKeySafetoAbstractItemNormalizer. - Antoine Bluchet (@soyuka) — extended the gate to JSON:API and HAL normalizers.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | api-platform/core | ≥ 2.6.0&&< 4.1.29 | 4.1.29 |
| 🐘Packagist | api-platform/core | ≥ 4.2.0&&< 4.2.25 | 4.2.25 |
| 🐘Packagist | api-platform/core | ≥ 4.3.0&&< 4.3.8 | 4.3.8 |
| 🐘Packagist | api-platform/json-api | ≥ 4.0.0&&< 4.1.29 | 4.1.29 |
| 🐘Packagist | api-platform/json-api | ≥ 4.2.0&&< 4.2.25 | 4.2.25 |
| 🐘Packagist | api-platform/json-api | ≥ 4.3.0&&< 4.3.8 | 4.3.8 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for api-platform/core. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update api-platform/core to 4.1.29 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-pjhx-3c3w-9v23 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-pjhx-3c3w-9v23 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-pjhx-3c3w-9v23. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-pjhx-3c3w-9v23 in your dependencies?
O3 detects GHSA-pjhx-3c3w-9v23 across Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.