SB2026101516 - Uncontrolled Recursion in Symfony

Description

This security bulletin contains information about 1 vulnerability.

1) Uncontrolled Recursion (CVE-ID: CVE-2026-109449)

CWE-ID: CWE-674 - Uncontrolled Recursion

CVSSv4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

The vulnerability allows a remote attacker to cause a denial of service by crashing the PHP process.

The vulnerability exists due to uncontrolled node-tree depth in the ExpressionLanguage parser when parsing untrusted expressions. A remote attacker can submit expressions containing deeply nested unary operators, array literals, binary operators or property accesses to cause a denial of service by crashing the PHP process.

The ExpressionSyntax validation constraint passes user-supplied expressions to ExpressionLanguage::lint(), exposing applications that validate such expressions to exploitation through a single request.

Remediation

Install update from vendor's website.

References

• https://github.com/symfony/symfony/security/advisories/GHSA-7rpj-w9pf-39rr
• https://github.com/symfony/symfony/commit/c2c00c5c15602aa2df98c3e2b313570ab5f26a33