PyJWT.decode() reintroduces options-dict mutation, enabling silent claim-verification bypass on dict reuse

SummaryPyJWT.decode/decodecomplete mutates a caller-supplied options dict in place whenever verifysignature is falsy, adding verifyexp/verifynbf/verifyiat/verifyaud/verifyiss/verifysub/verifyjti keys directly onto that object. If application code reuses the same options dict across calls a config...

CVE-2026-48523: Improper Verification of Cryptographic Signature

PyJWT is a JSON Web Token implementation in Python. From 2.9.0 to 2.12.1, there is a verifier-side algorithm allow-list bypass when jwt.decode or jwt.decodecomplete are called with a PyJWK key. The token header alg is checked against the caller-supplied algorithms allow-list, but signature...