CVE-2025-66621 Details
Description
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.
A vulnerability exists in Apache James SASL OAuthBearer/XOAUTH2 in versions prior to 3.9.1, where the AUD claim in JWT payloads is not properly validated when introspection is not enabled. This flaw allows an attacker with valid credentials to gain unauthorized access to the mail server. Users are advised to upgrade to a version that requires explicit configuration of AUD claims and enables introspection.
Users should upgrade to Apache James version 3.9.1 or later, which addresses this vulnerability by requiring explicit configuration of AUD claims and enabling introspection.
Metrics
CVSS 4.0 Severity and Vector Strings:
VolerionCVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
Volerion
Assessed Nov 6, 2026References to Advisories, Solutions, and Tools
By selecting these links, you will be leaving this site. These are references gathered from the official CVE record and are not endorsed by Volerion.
| URL | Source(s) | Tag(s) |
|---|---|---|
| http://www.openwall.com/lists/oss-security/2026/11/06/13 | CVE | AdvisoryMailing ListRemedy |
| https://lists.apache.org/thread.html/xz1g0blzcbxod69oktyq84h7t06xzov6 | [email protected] | AdvisoryMailing ListRemedyVendor |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-345 | Insufficient Verification of Data Authenticity | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| Apache James | >= 3.9.0, < 3.9.1 (semver) |
CPE
Remediation
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Change History
2 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Nov 6, 2026 | CVE Modified | CVE |
| Nov 6, 2026 | New CVE Received | [email protected] |