CVE-2026-27962criticalCWE-347

CVE-2026-27962: falha crítica em authlib

Authlib JWS JWK Header Injection: Signature Verification Bypass

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28Vexday Risk Score

Sem sinal de exploração. Nenhum artefato público de exploração conhecido até agora.

ssvc Trackcvss 9.1epss 0.6%
Authlib is a Python library which builds OAuth and OpenID Connect servers. Prior to version 1.6.9, a JWK Header Injection vulnerability in authlib's JWS implementation allows an unauthenticated attacker to forge arbitrary JWT tokens that pass signature verification. When key=None is passed to any JWS deserialization function, the library extracts and uses the cryptographic key embedded in the attacker-controlled JWT jwk header field. An attacker can sign a token with their own private key, embed the matching public key in the header, and have the server accept the forged token as cryptographically valid — bypassing authentication and authorization entirely. This issue has been patched in version 1.6.9.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Produtos afetados
authlib · authlib
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