What’s Vulnerable › Vulnerabilities

CVE-2023-46734: Symfony potential Cross-site Scripting vulnerabilities in CodeExtension filters

• Severity: medium (CVSS 6.1 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.7% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2023-11-10 · updated 2026-07-29
• Weakness: CWE-79

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 products

• Debian Linux: 10.0
• symfony: from 2.0.0 before 4.4.51; from 5.0.0 before 5.4.31; from 6.0.0 before 6.3.8 — fixed in 4.4.51, 5.4.31, 6.3.8
• symfony Twig-Bridge: from 2.0.0 before 4.4.51; from 5.0.0 before 5.4.31; from 6.0.0 before 6.3.8 — fixed in 4.4.51, 5.4.31, 6.3.8

How to fix

Upgrade to a fixed version: symfony 4.4.51, 5.4.31, 6.3.8; symfony Twig-Bridge 4.4.51, 5.4.31, 6.3.8. Check the vendor advisory for mitigations.

References

• https://github.com/symfony/symfony/commit/5d095d5feb1322b16450284a04d6bb48d1198f54
• https://github.com/symfony/symfony/commit/9da9a145ce57e4585031ad4bee37c497353eec7c
• https://github.com/symfony/symfony/security/advisories/GHSA-q847-2q57-wmr3
• https://lists.debian.org/debian-lts-announce/2023/11/msg00019.html
• https://github.com/symfony/symfony/commit/5d095d5feb1322b16450284a04d6bb48d1198f54
• https://github.com/symfony/symfony/commit/9da9a145ce57e4585031ad4bee37c497353eec7c
• https://github.com/symfony/symfony/security/advisories/GHSA-q847-2q57-wmr3
• https://lists.debian.org/debian-lts-announce/2023/11/msg00019.html

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