Medium 6.5Published Mar 16, 2026

CVE-2026-28490Authlib is a Python library which builds OAuth and OpenID Connect servers.

Updated under an hour ago (2026-10-19 08:50 UTC)

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No exploitation reported and no EPSS estimate yet.

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Every CVE for authlib

Exploited in the last 30 days

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.

CVSS: 6.5 MEDIUM (v3.1, NVD)CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N
Weakness (CWE): CWE-203, CWE-327
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: Not given
NVD analysis: Analyzed
Record last updated: Jun 17, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

authlib authlib authlib:authlib	before 1.6.9	NVD

References

https://github.com/authlib/authlib/commit/48b345f29f6c459f11c6a40162b6c0b742ef2e22patch
https://github.com/authlib/authlib/releases/tag/v1.6.9product, release-notes
https://github.com/authlib/authlib/security/advisories/GHSA-7432-952r-cw78exploit, mitigation, vendor-advisory

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.