CVE-2026-96760: Authlib · Improper Verification of Cryptographic Signature
Affects AuthlibSource CVE Database V5
Not known to be exploited · CVSS 9.8 Critical.
Data as of 11 Nov 2026, 16:04 UTC
Thin evidence
One scorer or none| CISA-ADP | CVSS 3.1 | 9.8 |
|---|
- CISA SSVC
- Exploitation
- No evidence of active exploitation and no public proof of concept
- Automatable
- Attackers can reliably automate steps 1–4 of the kill chain
- Technical impact
- Total control over the software or total information disclosure
CISA SSVC assessment, 2026-10-01.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 28 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 11 Nov 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| AuthlibAuthlib | Affected
| Fixed in– |
AI-suggested
Users should avoid using Authlib version 1.8.0 and earlier for signature verification until a fix is released. Monitor the vendor advisory at https://kb.cert.org/vuls/id/762428 for updates and apply any official patches once available.
Description
Authlib version 1.8.0 and earlier contains a critical vulnerability in its JsonWebSignature.deserialize_json() method, which bypasses signature verification. This flaw allows the method to return the payload as successfully verified without actually checking the signature or requiring a cryptographic key.