fast-jwt: Incomplete patch of CVE-2026-34950: Non-whitespace key-prefix re-enables RSA→HS256 algorithm confusion
High-risk advisory
CVE-2026-107722
Summary
fast-jwt: Incomplete patch of CVE-2026-34950: Non-whitespace key-prefix re-enables RSA→HS256 algorithm confusion
Why it matters
GitHub has published a reviewed security advisory for fast-jwt. Prioritize it with other application dependency updates, especially because EPSS places it in the 18% percentile.
Operator check
Check whether fast-jwt is present in application dependency manifests, lockfiles, or build images. Review the GitHub advisory and upgrade to a patched version where available. EPSS probability: 0.3%; percentile: 18%.
Sources
PatchBrief uses public sources. It does not scan environments, verify exposure, or replace vendor guidance.