CVE-2026-109449
Severity not reportedIn 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…
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.
Affected products
Not reported by the source (unknown — not "none").
Weakness classification (CWE)
Source: NVD / CISA. “NVD-CWE-Other” and “NVD-CWE-noinfo” mean NVD could not assign a specific weakness.
Mitigation & advisories
No vendor advisory or patch reference tagged by NVD. Check the references below.
References
- https://github.com/symfony/symfony/pull/65690 596c5446-0ce5-4ba2-aa66-48b3b757a647
- https://github.com/symfony/symfony/pull/66720 596c5446-0ce5-4ba2-aa66-48b3b757a647
- https://github.com/symfony/symfony/pull/66723 596c5446-0ce5-4ba2-aa66-48b3b757a647
- https://github.com/symfony/symfony/security/advisories/GHSA-7rpj-w9pf-39rr 596c5446-0ce5-4ba2-aa66-48b3b757a647
- https://symfony.com/blog/cve-2026-109449-unbounded-nesting-in-the-expression-parser-lets-u... 596c5446-0ce5-4ba2-aa66-48b3b757a647