CVE-2026-114618
Published:October 22, 2026
Updated:October 23, 2026
Authlib is a Python library which builds OAuth and OpenID Connect servers. Prior to 1.9.0, the default RFC 7523 JWTBearerGrant.get_audiences() returns an empty list, causing JWTBearerGrant.verify_claims() to require only that an aud claim exists without matching the current authorization server. An attacker holding a legitimate assertion for another service can present it to a server that shares the signing key and uses the default grant, obtaining an access token across a trust boundary. Implementations that override get_audiences() with the server's valid audience identifiers are not affected. This issue is fixed in version 1.9.0.
Affected Packages
authlib (CONDA):
Affected version(s) >=1.0.0 <1.9.0Fix Suggestion:
Update to version 1.9.0https://github.com/authlib/authlib.git (GITHUB):
Affected version(s) >=v1.0.0 <v1.9.0Fix Suggestion:
Update to version v1.9.0authlib (PYTHON):
Affected version(s) >=1.0.0a1 <1.9.0Fix Suggestion:
Update to version 1.9.0Related Resources (4)
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Contact UsCVSS v4
Base Score:
7.6
Attack Vector
NETWORK
Attack Complexity
HIGH
Attack Requirements
NONE
Privileges Required
LOW
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:
6.8
Attack Vector
NETWORK
Attack Complexity
HIGH
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
NONE