joserfc vulnerabilities
4 known CVE vulnerabilities in joserfc, translated and rated.
- CVE-2026-75509Medium
joserfc, a Python library implementing JOSE standards, prior to version 1.7.3, has a vulnerability in JWTClaimsRegistry that applies membership matching to list-valued iss and sub claims, allowing an array-valued iss containing the expected issuer to pass an intended equality check and enabling issuer-validation bypass.
- CVE-2026-62995Low
The Python library joserfc versions 1.7.1 and earlier accept JWTs with trailing padding (==), which is non-conforming to JOSE specifications. This leads to token malleability, potentially allowing bypass of token revocation or anti-replay protection.
- CVE-2026-49852High
Vulnerability in the joserfc Python library before version 1.6.8 allows an attacker to forge HMAC tokens when the verification key is an empty string or None. The library does not reject zero-length keys, allowing signature verification bypass.
- CVE-2026-48990Medium
The joserfc library in versions 1.3.4 through 1.6.5 accepts oversized JWS payloads without proper length checks, potentially leading to resource exhaustion. This issue has been fixed in version 1.6.7.

