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CVE-2026-28802

critical

Authlib is a Python library which builds OAuth and OpenID Connect servers.

Vendor / product: Authlib — authlib

Authlib is a Python library which builds OAuth and OpenID Connect servers. From version 1.6.5 to before version 1.6.7, previous tests involving passing a malicious JWT containing alg: none and an empty signature was passing the signature verification step without any changes to the application code when a failure was expected.. This issue has been patched in version 1.6.7.

CVSS
9.8
9.8 (CVSS v3.1)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Severity source: NVD CVSS v3.1 (nvd@nist.gov)
Timeline (UTC)
Published: 2026-03-06 07:16
Modified: 2026-09-10 13:18
NVD status: Modified
Last synced 3 days ago
Verified against the source API 2026-10-27 07:07 UTC
Exploitation
Not listed in CISA KEV (as of last catalog sync)
Absence from KEV does not mean a CVE is not exploited. Exploitation status: unknown (no authoritative evidence in our sources).

Affected products

authlib / authlib ≥1.6.5 <1.6.7

Weakness classification (CWE)

CWE-347

Source: NVD / CISA. “NVD-CWE-Other” and “NVD-CWE-noinfo” mean NVD could not assign a specific weakness.

Mitigation & advisories

Vendor advisory: https://github.com/authlib/authlib/security/advisories/GHSA-7wc2-qxgw-g8gg
Patch / mitigation: https://github.com/authlib/authlib/commit/a61c2acb807496e67f32051b5f1b1d5ccf8f0a75
Patch / mitigation: https://github.com/authlib/authlib/commit/b87c32ed07b8ae7f805873e1c9cafd1016761df7

References

Data sources

NVD CVE API 2.0 — fetched 2026-10-27 07:07 UTC · record ↗

Learn the basics

Understanding CVEs and CVSS Scores

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