Authlib library contains a signature‑verification bypass vulnerability (Authlib Authlib)
At a glance
- Source
- NVD
- EPSS
- EPSS 0.43 % · percentile 38 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- certcc
- NVD status
- Awaiting Analysis
Description
Authlib (v1.7.2 and below) contains a signature verification bypass vulnerability. The JsonWebSignature.deserialize_json() method accepts a JSON Serialization JWS object and returns the payload as successfully verified without checking for a signature and without requiring a cryptographic key.
Weaknesses (CWE)
- CWE-347 — Improper Verification of Cryptographic Signature
- CWE-670 — Always-Incorrect Control Flow Implementation
- CWE-358 — Improperly Implemented Security Check for Standard
- CWE-20 — Improper Input Validation
References
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 3.1 | CRITICAL 9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H | CISA-ADP |
| CVSS 3.1 | CRITICAL 9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H | NVD · 134c704f-9b21-4f2e-91b3-4a467353bcc0 (Secondary) |
Advisories
- GHSA-6v38-4h7w-rj9h — Authlib: empty signatures validation in JWS JSON deserialization
European references
- ENISA EUVD · EUVD-2026-88465
- GCVE · GCVE-0-2026-96760
CERT-FR advisories
- CERTFR-2026-AVI-1433 — Multiples vulnérabilités dans les produits IBM · cert.ssi.gouv.fr
Affected products
| Product | Versions |
|---|---|
| Authlib · Authlib | affected 1.7.2 |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| CERT-FR (ANSSI) | Licence Ouverte / Etalab 2.0 |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |