CVE-2023-46734
MEDIUMCVE-2023-46734 is a medium-severity (CVSS 6.1) Cross-site Scripting (XSS) vulnerability in symfony/twig-bridge. O3 Security confirms whether CVE-2023-46734 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Symfony potential Cross-site Scripting vulnerabilities in CodeExtension filters
Blast Radius
symfony/twig-bridge🐘symfony/twig-bridge🐘symfony/twig-bridge🐘symfony/symfony🐘symfony/symfony🐘symfony/symfonyReal-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
Symfony is a PHP framework for web and console applications and a set of reusable PHP components. Starting in versions 2.0.0, 5.0.0, and 6.0.0 and prior to versions 4.4.51, 5.4.31, and 6.3.8, some Twig filters in CodeExtension use is_safe=html but don't actually ensure their input is safe. As of versions 4.4.51, 5.4.31, and 6.3.8, Symfony now escapes the output of the affected filters.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | symfony/twig-bridge | ≥ 2.0.0&&< 4.4.51 | 4.4.51 |
| 🐘Packagist | symfony/twig-bridge | ≥ 5.0.0&&< 5.4.31 | 5.4.31 |
| 🐘Packagist | symfony/twig-bridge | ≥ 6.0.0&&< 6.3.8 | 6.3.8 |
| 🐘Packagist | symfony/symfony | ≥ 2.0.0&&< 4.4.51 | 4.4.51 |
| 🐘Packagist | symfony/symfony | ≥ 5.0.0&&< 5.4.31 | 5.4.31 |
| 🐘Packagist | symfony/symfony | ≥ 6.0.0&&< 6.3.8 | 6.3.8 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for symfony/twig-bridge. 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 symfony/twig-bridge to 4.4.51 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-46734 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 CVE-2023-46734 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 CVE-2023-46734. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2023-46734 in your dependencies?
O3 detects CVE-2023-46734 across Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.