GHSA-24x9-r6q4-q93w
GHSA-24x9-r6q4-q93w is a CWE-693 vulnerability in twig/twig. O3 Security confirms whether GHSA-24x9-r6q4-q93w is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Twig: `template_from_string()` escapes a SourcePolicy-driven sandbox via synthesized template name
Exploitation Status
No confirmed exploitation observed yet
- 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-24x9-r6q4-q93w.
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
When the sandbox is enabled selectively via SourcePolicyInterface (and not globally), a sandboxed template that is allowed to call template_from_string and include can render an arbitrary inner template with no security policy enforcement.
Environment::createTemplate() compiles the inner string under a synthesized name (__string_template__<hash>), so a name/path-based SourcePolicy returns false for it, and the inner template's checkSecurity() becomes a no-op. From a template the integrator believes is sandboxed, an attacker can use any tag/filter/function (including constant() to read secrets, or |map("system") to execute shell commands).
Resolution
This is a configuration trap rather than a code bug: there is no legitimate use case for exposing template_from_string to untrusted template authors, and propagating the parent sandbox state through template_from_string would require invasive changes to SourcePolicyInterface semantics with their own risks.
Starting with Twig 3.26.0, the documentation and the PHPDoc of StringLoaderExtension::templateFromString() explicitly warn against allowing template_from_string in a sandboxed environment (i.e. listing it in a SecurityPolicy allowed-functions list). Integrators using a SourcePolicyInterface MUST NOT allow template_from_string in their allowed functions; the safest option is not to register StringLoaderExtension at all when a sandbox is in use.
Credits
Twig would like to thank Claude Mythos Preview (via Project Glasswing) for reporting the issue.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | twig/twig | ≥ 3.9.0&&< 3.26.0 | 3.26.0 |
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 3.26.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-24x9-r6q4-q93w 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-24x9-r6q4-q93w 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-24x9-r6q4-q93w. 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-24x9-r6q4-q93w in your dependencies?
O3 detects GHSA-24x9-r6q4-q93w across Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.