CVE-2024-37568

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2024-06-09 · updated 2026-06-17
Weakness: CWE-347

Description

lepture Authlib before 1.3.1 has algorithm confusion with asymmetric public keys. Unless an algorithm is specified in a jwt.decode call, HMAC verification is allowed with any asymmetric public key. (This is similar to CVE-2022-29217 and CVE-2024-33663.)

Affected products

authlib: before 1.3.1 — fixed in 1.3.1

How to fix

Upgrade to a fixed version: authlib 1.3.1. Check the vendor advisory for mitigations.

References

https://github.com/lepture/authlib/issues/654
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/FHJI32SN4FNAUVNALVGOKWHNSQ6XS3M5/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/IZI7HYGN7VZAYFV6UV3SRLYF7QGERXIU/
https://www.vicarius.io/vsociety/posts/algorithm-confusion-in-lepture-authlib-cve-2024-37568
https://github.com/lepture/authlib/issues/654
https://lists.debian.org/debian-lts-announce/2025/10/msg00032.html
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/FHJI32SN4FNAUVNALVGOKWHNSQ6XS3M5/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/IZI7HYGN7VZAYFV6UV3SRLYF7QGERXIU/
https://www.vicarius.io/vsociety/posts/algorithm-confusion-in-lepture-authlib-cve-2024-37568

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