CVE-2026-75973: Apache Tomcat: Cross-context authentication mix-up with Jakarta Authentication configured
Improper Authentication vulnerability in Apache Tomcat. When Jakarta Authentication was configured with SimpleAuthConfigProvider as the default provider and multiple web application used that provider, the realm for the first web application to authenticate a request would be used for all web applications.
This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.25, from 10.1.0-M1 through 10.1.59, from 9.0.0.M4 through 9.0.121.
The following versions were EOL at the time the CVE was created but are known to be affected: from 8.5.0 through 8.5.100. Other unsupported versions may also be affected.
Users are recommended to upgrade to version 11.0.26, 10.1.60, 9.0.122, which fixes the issue.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
Apache Tomcatto a version that resolves this vulnerability.Fixed in 11.0.26 - Upgrade
Upgrade
Apache Tomcatto a version that resolves this vulnerability.Fixed in 10.1.60 - Upgrade
Upgrade
Apache Tomcatto a version that resolves this vulnerability.Fixed in 9.0.122
Event History
Frequently Asked Questions
Which deployments are exposed to this issue?
The issue applies when Jakarta Authentication is configured with SimpleAuthConfigProvider as the default provider and multiple web applications use that provider. In that configuration, the realm selected by the first application to authenticate a request can be reused for other web applications.
Which releases contain the fix?
Upgrade to Apache Tomcat 11.0.26, 10.1.60, or 9.0.122. Affected release ranges include 11.0.0-M1 through 11.0.25, 10.1.0-M1 through 10.1.59, and 9.0.0.M4 through 9.0.121.
Are unsupported Tomcat versions relevant?
Tomcat 8.5.0 through 8.5.100 is known to be affected, although it was end-of-life when the CVE was created. Other unsupported versions may also be affected.