CVE-2026-114616
Published:October 22, 2026
Updated:October 23, 2026
Authlib is a Python library which builds OAuth and OpenID Connect servers. Prior to 1.9.1, Authlib's OctKey.import_key() and HMAC signing and verification path accept zero-length key material. If an application's secret lookup can return an empty string or empty bytes, a remote attacker can compute the deterministic HS256, HS384, or HS512 signature for arbitrary token claims and have Authlib treat the token as authentic. This issue is fixed in version 1.9.1.
Affected Packages
authlib (CONDA):
Affected version(s) >=1.0.0 <1.9.1Fix Suggestion:
Update to version 1.9.1https://github.com/authlib/authlib.git (GITHUB):
Affected version(s) >=v1.0.0 <v1.9.1Fix Suggestion:
Update to version v1.9.1authlib (PYTHON):
Affected version(s) >=1.0.0a1 <1.9.1Fix Suggestion:
Update to version 1.9.1Related Resources (3)
Do you need more information?
Contact UsCVSS v4
Base Score:
9.1
Attack Vector
NETWORK
Attack Complexity
HIGH
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
NONE
Vulnerable System Confidentiality
HIGH
Vulnerable System Integrity
HIGH
Vulnerable System Availability
NONE
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
7.4
Attack Vector
NETWORK
Attack Complexity
HIGH
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
NONE