CVE-2025-66621: Apache James SASL OAuthBearer/XOAUTH2 prior versions 3.9.1 fails to validate correctly AUD claim of
Source GCVE Database
Not known to be exploited : upgrade to 3.9.1 soon.
Data as of 6 Nov 2026, 13:23 UTC
Rated High by Threat Radar's AI analysis · CVSS not yet scored by NVD
Thin evidence
One scorer or none- Patch
- Available – fixed in 3.9.1
Exploitation evidence
Disclosed: evidence found.
CVE published 6 Nov 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 6 Nov 2026.
What to do
Upgrade Apache James and org.apache.james/apache-james-server to 3.9.1.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Apache Software FoundationApache James | Affected
| Fixed in
|
Mavenorg.apache.james/apache-james-serverpkg:maven/org.apache.james/apache-james-serverOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Upgrade Apache James SASL OAuthBearer/XOAUTH2 to version 3.9.1 or later, which fixes the AUD claim validation issue by enforcing explicit configuration and token introspection. No other mitigation steps are indicated.
Description
Apache James SASL OAuthBearer/XOAUTH2 versions prior to 3.9.1 do not correctly validate the AUD claim in JWT payloads when introspection is not configured. This flaw allows attackers with valid credentials to access the mail server without proper authorization. Users are advised to upgrade to version 3.9.1 or later, which enforces explicit AUD claim configuration and introspection.