fast-jwt: Incomplete patch of CVE-2026-34950: Non-whitespace key-prefix re-enables RSA→HS256 algorithm confusion

Summary The fix for CVE-2026-34950 CVSS 9.1, released in v6.2.0 is incomplete. It adds key.trim to the PEM-detection path in src/crypto.js, but String.prototype.trim only strips characters classified as whitespace by the ECMAScript specification. The subsequent ^-anchored regex /^-----BEGIN?: RSA...

PyJWT: Asymmetric-PEM detection bypass: whitespace/line-ending-mutated public keys skip the HS/asymmetric confusion guard

Prerequisites both conditions must hold; both are deployment properties, not attacker-controlled at request time:- The jwt.decode allow-list mixes an HMAC algorithm with an asymmetric one, e.g. algorithms="ES256", "HS256" the RFC 8725 footgun the guard exists to backstop.- The verification key is...

PYSEC-2026-4145 PyJWT: Asymmetric-PEM detection bypass: whitespace/line-ending-mutated public keys skip the HS/asymmetric confusion guard

Prerequisites both conditions must hold; both are deployment properties, not attacker-controlled at request time: - The jwt.decode allow-list mixes an HMAC algorithm with an asymmetric one, e.g. algorithms="ES256", "HS256" the RFC 8725 footgun the guard exists to backstop. - The verification key ...

PyJWT: Asymmetric-PEM detection bypass: whitespace/line-ending-mutated public keys skip the HS/asymmetric confusion guard

Prerequisites both conditions must hold; both are deployment properties, not attacker-controlled at request time: - The jwt.decode allow-list mixes an HMAC algorithm with an asymmetric one, e.g. algorithms="ES256", "HS256" the RFC 8725 footgun the guard exists to backstop. - The verification key ...