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CVE-2026-109449

Symfony: Unbounded Nesting in the Expression Parser Lets Untrusted Expressions Crash the Process PUBLISHED

Description (CNA)

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 (CNA)

Vendor / productVersions
sensiolabs / symfonyaffected 0 before v5.4.54; affected v6.0.0-BETA1 before v6.4.48; affected v7.0.0-BETA1 before v7.4.21; affected v8.0.0-BETA1 before v8.1.9

CWE

CWE-674

References

ADP enrichment

CISA-ADP

No English description supplied.

No references supplied.