GHSA-p42q-9prx-q5wq
GHSA-p42q-9prx-q5wq is a CWE-693 vulnerability in twig/twig. O3 Security confirms whether GHSA-p42q-9prx-q5wq is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Twig: Sandbox state regression in deprecated internal wrappers in `src/Resources/core.php`
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- A successful exploit gives an attacker total control of the affected component, not partial access.
- 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-p42q-9prx-q5wq.
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.
Real-World Exposure
twig/twigReal-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
Description
The 3.26.0 source-policy hardening changed the signature of CoreExtension::checkArrow() to take a boolean $isSandboxed instead of an Environment, and added the same $isSandboxed argument to CoreExtension::arraySome() and CoreExtension::arrayEvery(). Compiled templates were updated to pass the per-source sandbox state computed at the call site.
The deprecated internal wrappers exposed in src/Resources/core.php for legacy third-party code (twig_check_arrow_in_sandbox(), twig_array_some(), twig_array_every()) were not updated:
twig_array_some()andtwig_array_every()callCoreExtension::arraySome()/arrayEvery()without forwarding the sandbox state. The underlying methods default$isSandboxedtofalse, so the callable-must-be-a-Closurerestriction is silently bypassed in sandbox mode and a string callable such as'strcmp'is accepted.twig_check_arrow_in_sandbox()passes theEnvironmentobject whereCoreExtension::checkArrow()now expects abool, which throws aTypeErroron PHP 8+.
Compiled Twig templates are not affected: they call CoreExtension::* directly with the correct arguments. Applications are only impacted if they still call the deprecated twig_* helpers on top of a sandboxed Environment.
Resolution
The three wrappers now resolve the current sandbox state via twig_resolve_is_sandboxed() (the same helper compiled templates use), and forward it to the corresponding CoreExtension::* method. twig_check_arrow_in_sandbox() no longer triggers a TypeError, and twig_array_some() / twig_array_every() now enforce the same sandbox restriction as compiled templates.
Credits
We would like to thank El Kharoubi Iosif for reporting the issue and Fabien Potencier for providing the fix.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | twig/twig | all versions | 3.27.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for twig/twig. 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 twig/twig to 3.27.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-p42q-9prx-q5wq 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-p42q-9prx-q5wq 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-p42q-9prx-q5wq. 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-p42q-9prx-q5wq in your dependencies?
O3 detects GHSA-p42q-9prx-q5wq across Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.