lepture Authlib before 1.3.1 has algorithm confusion with asymmetric public keys.
Priority HIGH 72CWE-284Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Security bypass, Information disclosure
- Confidentiality · integrity · availability
- None · High · None
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA and GitHub. Impact type from CWE-284 and CWE-327.
Summary
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.)
Why it matters now
Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00388 33rd percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Fixed authlib (PyPI): 1.3.1
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | — | all versions | — | No fix listed | CNA |
| — | authlib (PyPI) | before 1.3.1 | 1.3.1 | Patch available | GHSA-5357-c2jx-v7qh |
- — Vendor— Affected all versions Fixed in — No fix listed CNA
- authlib (PyPI) Vendor— Affected before 1.3.1 Fixed in 1.3.1 Patch available GHSA-5357-c2jx-v7qh
Remediation
- Fix · GHSA-5357-c2jx-v7qh authlib (PyPI) Fixed in 1.3.1 Advisory →
Vendor assessments
Timeline
- 2026-10-02 Threatist record created from CVE-2024-37568
- 2026-10-03 Alias added: GHSA-5357-c2jx-v7qh
References
Advisory 3
Other 6
- https://www.vicarius.io/vsociety/posts/algorithm-confusion-in-lepture-authlib-cve-2024-37568
- https://github.com/lepture/authlib
- https://github.com/pypa/advisory-database/tree/main/vulns/authlib/PYSEC-2024-52.yaml
- 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
More Authlib vulnerabilities
- TI-2026-22305 Authlib JWS JWK Header Injection: Signature Verification Bypass CVSS 3.1CRITICAL 9.1
- TI-2026-79518 Authlib fix bypass lets attackers forge HS256 tokens with PEM keys CVSS 3.1CRITICAL 9.1
- TI-2025-36973 Authlib: JWS/JWT accepts unknown crit headers (RFC violation → possible authz bypass) CVSS 3.1HIGH 7.5
- TI-2025-41738 Authlib: 1-click Account Takeover CVSS 3.1HIGH 8.8
- TI-2026-22761 Authlib: Fail-Open Cryptographic Verification in OIDC Hash Binding CVSS 4.0HIGH 8.2
- TI-2026-22754 Authlib Vulnerable to JWE RSA1_5 Bleichenbacher Padding Oracle CVSS 4.0HIGH 8.3
Sources
- CVE-2024-37568 · CVE Program
- CVE-2024-37568 · NVD
- FIRST EPSS
- GHSA-5357-c2jx-v7qh · GitHub Advisory Database · CC BY 4.0
- CVE-2024-37568 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences