CVE-2025-66621
Apache James: SASL OAUTHBEARER do not validate aud in JWT payload if misconfigred
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.
INFO
Published Date :
Nov. 6, 2026, 12:17 p.m.
Last Modified :
Nov. 6, 2026, 12:17 p.m.
Remotely Exploit :
No
Source :
[email protected]
Solution
- Upgrade Apache James to version 3.9.1 or later.
- Configure aud claims validation.
- Enforce introspection for JWT validation.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2025-66621.
| URL | Resource |
|---|---|
| https://lists.apache.org/thread.html/xz1g0blzcbxod69oktyq84h7t06xzov6 |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2025-66621 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2025-66621
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2025-66621 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2025-66621 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by [email protected]
Nov. 06, 2026
Action Type Old Value New Value Added 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. Added CWE CWE-345 Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2025/66xxx/CVE-2025-66621.json">CVE-2025-66621</a> Added Reference https://lists.apache.org/thread.html/xz1g0blzcbxod69oktyq84h7t06xzov6