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.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
Vendor advisory: debian — https://security-tracker.debian.org/tracker/CVE-2026-28490
Vendor advisory: suse — https://www.suse.com/security/cve/CVE-2026-28490.html
OS impact
| OS | Version | Status | Fixed in |
|---|---|---|---|
| sles | affected | | |
| debian | bookworm | affected | |
| debian | bullseye | fixed | 0.15.4-1+deb11u2 |
| debian | forky | fixed | 1.6.9-1 |
| debian | sid | fixed | 1.6.9-1 |
| debian | trixie | affected | |
Package impact
| Ecosystem | Package | Vulnerable | Fixed |
|---|---|---|---|
| PyPI | authlib | <1.6.9 | 1.6.9 |
References
- https://github.com/authlib/authlib/security/advisories/GHSA-7432-952r-cw78
- https://nvd.nist.gov/vuln/detail/CVE-2026-28490
- https://github.com/authlib/authlib/commit/48b345f29f6c459f11c6a40162b6c0b742ef2e22
- https://github.com/authlib/authlib
- https://github.com/authlib/authlib/releases/tag/v1.6.9
- https://www.suse.com/security/cve/CVE-2026-28490.html
- https://security-tracker.debian.org/tracker/CVE-2026-28490
Verify integrity in audit chain (admin only). AS-IS.