CVE-2025-65015

NameCVE-2025-65015
Descriptionjoserfc is a Python library that provides an implementation of several JSON Object Signing and Encryption (JOSE) standards. In versions from 1.3.3 to before 1.3.5 and from 1.4.0 to before 1.4.2, the ExceededSizeError exception messages are embedded with non-decoded JWT token parts and may cause Python logging to record an arbitrarily large, forged JWT payload. In situations where a misconfigured — or entirely absent — production-grade web server sits in front of a Python web application, an attacker may be able to send arbitrarily large bearer tokens in the HTTP request headers. When this occurs, Python logging or diagnostic tools (e.g., Sentry) may end up processing extremely large log messages containing the full JWT header during the joserfc.jwt.decode() operation. The same behavior also appears when validating claims and signature payload sizes, as the library raises joserfc.errors.ExceededSizeError() with the full payload embedded in the exception message. Since the payload is already fully loaded into memory at this stage, the library cannot prevent or reject it. This issue has been patched in versions 1.3.5 and 1.4.2.
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
forky1.4.1-1vulnerable
sid1.4.3-1vulnerable

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

PackageTypeReleaseFixed VersionUrgencyOriginDebian Bugs
joserfcsource(unstable)(unfixed)

Notes

https://github.com/authlib/joserfc/security/advisories/GHSA-frfh-8v73-gjg4
Fixed by: https://github.com/authlib/joserfc/commit/63932f169d924caffafa761af2122b82059017f7 (1.4.2)
Fixed by: https://github.com/authlib/joserfc/commit/673c8743fd0605b0e1de6452be6cba75f44e466b (1.3.5)

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