CVE-2025-66621
Published:November 06, 2026
Updated:November 09, 2026
Apache James SASL OAuthBearer/XOAUTH2 prior versions 3.9.1 fails to validate correctly AUD claim of JWT payloads when introspection is not configured.
This allows an attacker with valid credentials to access the mail server even if they are not authorized to do so.
We recommend users to upgrade to non vulnerable version that forces explicit configuration of aud claims and forces introspection.
Affected Packages
https://github.com/apache/james-project.git (GITHUB):
Affected version(s) >=james-project-3.7.0 <james-project-3.9.1Fix Suggestion:
Update to version james-project-3.9.1org.apache.james:james-server-jwt (JAVA):
Affected version(s) >=3.7.0 <3.9.1Fix Suggestion:
Update to version 3.9.1Related Resources (2)
Do you need more information?
Contact UsCVSS v4
Base Score:
7.1
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
LOW
User Interaction
NONE
Vulnerable System Confidentiality
HIGH
Vulnerable System Integrity
LOW
Vulnerable System Availability
NONE
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
7.1
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
LOW
Availability
NONE
Weakness Type (CWE)
Insufficient Verification of Data Authenticity
EPSS
Base Score:
0.14