GHSA-45vw-wh46-2vx8
GHSA-45vw-wh46-2vx8 is a Code Injection vulnerability in twig/twig. O3 Security confirms whether GHSA-45vw-wh46-2vx8 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Twig: Arbitrary PHP code execution via `_self.(<string>)` macro-reference compilation
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-45vw-wh46-2vx8.
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 obj.(expr) dynamic-attribute syntax (added in 3.15.0 as the replacement for the deprecated attribute() function) lets the attribute be an arbitrary expression. When the receiver is _self (or any {% import %} alias) and the parenthesised expression is a string literal, DotExpressionParser short-circuits to the macro-call path and concatenates the attacker-controlled string into a MacroReferenceExpression name with no identifier validation. MacroReferenceExpression::compile() then emits that name raw into the generated PHP source.
An attacker who can supply template source can inject arbitrary PHP into the compiled template and execute it at template-load time, before checkSecurity() is ever called. This is a complete bypass of SandboxExtension, including a globally-enabled sandbox with an empty SecurityPolicy allowlist.
Resolution
The parser now validates that the dynamic attribute resolves to a valid macro identifier before routing through MacroReferenceExpression, and the macro-reference compiler emits the name through a properly escaped path.
Credits
Twig would like to thank Claude Mythos Preview (via Project Glasswing) for reporting the issue and providing the fix.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | twig/twig | ≥ 3.15.0&&< 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-45vw-wh46-2vx8 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-45vw-wh46-2vx8 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-45vw-wh46-2vx8. 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-45vw-wh46-2vx8 in your dependencies?
O3 detects GHSA-45vw-wh46-2vx8 across Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.