Critical severity · published Sep 28, 2026
CVE-2026-96760
Authlib library contains a signature‑verification bypass vulnerability
9.8
CVSS
0.4%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 32% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
AU
Authlib · Authlib
1.7.2 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-96760
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-96760
github.com
https://github.com/authlib/authlib
kb.cert.org
https://kb.cert.org/vuls/id/762428
More from Authlib
9.8
CVE-2026-104056
Authlib version 1.7.2 and below contains a vulnerability where discovery JSON metadata is cached without validation or issuer-origin binding
9.8
CVE-2026-28802
Authlib: Setting `alg: none` and a blank signature appears to bypass signature verification
9.1
CVE-2026-27962
Authlib JWS JWK Header Injection: Signature Verification Bypass
8.8
CVE-2026-116672
Authlib RFC 7592 examples omit registration-access-token client binding
8.8
CVE-2025-68158
Authlib is a Python library which builds OAuth and OpenID Connect servers