CVEvulnerability

CVE-2026-114618

6.8 MEDIUM Published 2026-10-22 Modified 2026-10-29 Official page ↗
Status
Analyzed
Published
2026-10-22
Last modified
2026-10-29
Assigner
[email protected]
CVSS 3.1 ([email protected])
6.8 MEDIUM — CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N
Weaknesses
CWE-1188, CWE-287

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.

Affected configurations

• authlib authlib (< 1.9.0)

Related

Weakness · CWE (2)

  • CWE-1188 Initialization of a Resource with an Insecure Default weakness
  • CWE-287 Improper Authentication weakness

References