Symfony: Unbounded Recursion in the YAML Inline Lexer Lets a Single Document Crash the Process
High-risk advisory
CVE-2026-109413
Summary
Symfony: Unbounded Recursion in the YAML Inline Lexer Lets a Single Document Crash the Process
Why it matters
GitHub has published a reviewed security advisory for symfony/symfony. Prioritize it with other application dependency updates, especially because EPSS places it in the 34% percentile.
Operator check
Check whether symfony/symfony is present in application dependency manifests, lockfiles, or build images. Review the GitHub advisory and upgrade to a patched version where available. CVSS score: 8.7. EPSS probability: 0.4%; percentile: 34%.
Sources
PatchBrief uses public sources. It does not scan environments, verify exposure, or replace vendor guidance.