CVEvulnerability
CVE-2026-109449
8.7 HIGH
Official page ↗
- Status
- Awaiting Analysis
- Published
- 2026-10-15
- Last modified
- 2026-10-16
- Assigner
- 596c5446-0ce5-4ba2-aa66-48b3b757a647
- CVSS 4.0 (596c5446-0ce5-4ba2-aa66-48b3b757a647)
- 8.7 HIGH — 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
- Weaknesses
- CWE-674
Description
In Symfony Expression Language versions prior to 5.4.54, 6.4.48, 7.4.21, and 8.1.9, the parser of the ExpressionLanguage component built its node tree with no bound on its depth. An expression made of tens of thousands of nested unary operators, array literals, binary operators or property accesses crashed the PHP process, while the tree was being freed.
#[Assert\ExpressionSyntax] passes the validated value to ExpressionLanguage::lint(), so an application validating expressions written by its users could be crashed by a single request, and so could any code parsing untrusted expressions.
This issue affects symfony/expression-language through v5.4.53, v6.0.0-BETA1 through v6.4.47, v7.0.0-BETA1 through v7.4.20, and v8.0.0-BETA1 through v8.1.8.
Related
Weakness · CWE (1)
- CWE-674 Uncontrolled Recursion weakness
References
- https://github.com/symfony/symfony/pull/65690 github.com
- https://github.com/symfony/symfony/pull/66720 github.com
- https://github.com/symfony/symfony/pull/66723 github.com
- https://github.com/symfony/symfony/security/advisories/GHSA-7rpj-w9pf-39rr github.com
- https://symfony.com/blog/cve-2026-109449-unbounded-nesting-in-the-expression-parser-lets-untrusted-expressions-crash-the-process symfony.com