CVE-2026-114618
MEDIUM
MEDIUM
Priority: 0.02
BB Relevance:
54/100
Published: 2026-10-22
Modified: 2026-10-29
First seen: 2026-10-29
Status: active
Attack Surface
Network
No Interaction
Conf. Impact
Integ. Impact
CVSS Vector Breakdown
AV:
Network
AC:
High
PR:
Low
UI:
None
S:
Unchanged
C:
High
I:
High
A:
None
Description
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.