CVE-2026-55957: Apache Tomcat authentication bypass in JNDIRealm

CVE-2026-55957 · Severity: high · CVSS 7.3 · Published 2026-06-29

Apache Tomcat is a widely used web server and application container. A security flaw in its authentication mechanism allows unauthorized users to log in without providing a valid password when specific directory-based authentication settings are used. This could lead to unauthorized access to sensitive applications and data managed by the server.

Technologies: Apache Tomcat, org.apache.tomcat:tomcat (Maven), org.apache.tomcat:tomcat-catalina (Maven), org.apache.tomcat.embed:tomcat-embed-core (Maven). Vendors: Apache, Maven.

Quick answers

Is CVE-2026-55957 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-55957 being exploited in the wild.
How severe is CVE-2026-55957?
High severity, with a CVSS score of 7.3, published 29 June 2026.
Which products and versions are affected?
Apache Tomcat 11.0.0-M1 through 11.0.4, 10.1.0-M1 through 10.1.36, 9.0.0.M1 through 9.0.100, 8.5.0 through 8.5.100, 7.0.0 through 7.0.109; org.apache.tomcat:tomcat (Maven) >= 11.0.0-M1, < 11.0.5, ECOSYSTEM:introduced=11.0.0-M1,fixed=11.0.5; org.apache.tomcat:tomcat-catalina (Maven) >= 11.0.0-M1, < 11.0.5, ECOSYSTEM:introduced=11.0.0-M1,fixed=11.0.5; org.apache.tomcat.embed:tomcat-embed-core (Maven) >= 11.0.0-M1, < 11.0.5, ECOSYSTEM:introduced=11.0.0-M1,fixed=11.0.5.
Is there a fix for CVE-2026-55957?
Yes. org.apache.tomcat:tomcat (Maven): upgrade to 11.0.5 or later; org.apache.tomcat:tomcat-catalina (Maven): upgrade to 11.0.5 or later; org.apache.tomcat.embed:tomcat-embed-core (Maven): upgrade to 11.0.5 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-55957 attacked?
It is attacked over the network, in a software library.
Am I affected by CVE-2026-55957?
Check whether you run Apache Tomcat, org.apache.tomcat:tomcat (Maven), org.apache.tomcat:tomcat-catalina (Maven) or one of the others listed at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

  • org.apache.tomcat:tomcat (Maven): upgrade to 11.0.5 or later
    # set org.apache.tomcat:tomcat to 11.0.5 in your pom.xml or build.gradle
  • org.apache.tomcat:tomcat-catalina (Maven): upgrade to 11.0.5 or later
    # set org.apache.tomcat:tomcat-catalina to 11.0.5 in your pom.xml or build.gradle
  • org.apache.tomcat.embed:tomcat-embed-core (Maven): upgrade to 11.0.5 or later
    # set org.apache.tomcat.embed:tomcat-embed-core to 11.0.5 in your pom.xml or build.gradle

Technical details

A vulnerability classified as CWE-304 (Missing Critical Step in Authentication) exists in Apache Tomcat's JNDIRealm component. When the JNDIRealm is configured to authenticate binds using the Generic Security Service Application Program Interface (GSSAPI), the authentication logic fails to properly verify credentials. This allows a remote attacker to successfully authenticate to the application without providing the correct password. The issue affects multiple major versions of Tomcat. Users are advised to upgrade to versions 11.0.5, 10.1.37, or 9.0.101 to remediate the flaw.

Affected products

  • Apache Tomcat 11.0.0-M1 through 11.0.4, 10.1.0-M1 through 10.1.36, 9.0.0.M1 through 9.0.100, 8.5.0 through 8.5.100, 7.0.0 through 7.0.109

Identifiers

  • CVE-2026-55957
  • BIT-TOMCAT-2026-55957
  • GHSA-7895-gffq-w6jq

Timeline

  • 2026-06-29: disclosed
  • 2026-06-29: advisory

References

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