9.8

CVE-2026-28802

Exploit

Authlib: Setting `alg: none` and a blank signature appears to bypass signature verification

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.
Daten sind bereitgestellt durch National Vulnerability Database (NVD)
Authlib ≫ Authlib Version >= 1.6.5 < 1.6.7
VulnDex Vulnerability Enrichment
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Zu dieser CVE wurde keine Warnung gefunden.
EPSS Metriken
Typ Quelle Score Percentile
EPSS FIRST.org 0.34% 0.252
CVSS Metriken
Quelle Base Score Exploit Score Impact Score Vector String
nvd@nist.gov 9.8 3.9 5.9
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
security-advisories@github.com 7.7 0 0
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CWE-347 Improper Verification of Cryptographic Signature

The product does not verify, or incorrectly verifies, the cryptographic signature for data.

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