CVE-2026-28490

Name	CVE-2026-28490
Description	Authlib is a Python library which builds OAuth and OpenID Connect servers. Prior to version 1.6.9, a cryptographic padding oracle vulnerability was identified in the Authlib Python library concerning the implementation of the JSON Web Encryption (JWE) RSA1_5 key management algorithm. Authlib registers RSA1_5 in its default algorithm registry without requiring explicit opt-in, and actively destroys the constant-time Bleichenbacher mitigation that the underlying cryptography library implements correctly. This issue has been patched in version 1.6.9.
Source	CVE (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 Package	Release	Version	Status
python-authlib (PTS)	bullseye	0.15.4-1	vulnerable
	bullseye (security)	0.15.4-1+deb11u1	vulnerable
	bookworm	1.2.0-1	vulnerable
	trixie	1.6.0-1	vulnerable
	forky, sid	1.6.9-1	fixed

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

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
python-authlib	source	(unstable)	1.6.9-1

Notes

https://github.com/authlib/authlib/security/advisories/GHSA-7432-952r-cw78
Fixed by: https://github.com/authlib/authlib/commit/48b345f29f6c459f11c6a40162b6c0b742ef2e22 (v1.6.9)