CVE-2026-75509

NameCVE-2026-75509
Descriptionjoserfc is a Python library that provides an implementation of several JSON Object Signing and Encryption (JOSE) standards. Prior to version 1.7.3, JWTClaimsRegistry applies membership matching to list-valued iss and sub claims, allowing an array-valued iss that contains the expected issuer to pass an intended equality check and enabling issuer-validation bypass. This issue is fixed in version 1.7.3.
SourceCVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)

Vulnerable and fixed packages

The table below lists information on source packages.

Source PackageReleaseVersionStatus
joserfc (PTS)trixie1.1.0-1vulnerable
forky, sid1.7.4-1fixed

The information below is based on the following data on fixed versions.

PackageTypeReleaseFixed VersionUrgencyOriginDebian Bugs
joserfcsource(unstable)1.7.3-1

Notes

https://github.com/authlib/joserfc/security/advisories/GHSA-r74j-q665-7rpj
Fixed by: https://github.com/authlib/joserfc/commit/76ee6a59bf5773c0af00b99076c5e199031f97f1 (1.7.3)

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