Review reviewHigh

CVE-2026-55957

Apache Software Foundation Apache Tomcat, tomcat

Missing Critical Step in Authentication vulnerability in Apache Tomcat when the JNDIRealm was configured to authenticate binds using GSSAPI allowed attackers to authenticate without provided the correct password. This issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.4, from 10.1.0-M1 through 10.1.36, from 9.0.0.M1 through 9.0.100, from 8.5.0 through 8.5.100, from 7.0.0 through 7.0.109. Users are recommended to upgrade to version 11.0.5, 10.1.37 or 9.0.101, which fixes the issue.

CVSS: 7.3
EPSS: 0.46%
CISA KEV: Not listed
Published: 2026.06.30

PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV

Exploit probability0.46%

Technical severityCVSS 7.3

Vulnerability overview

Affected product and versions

Product: Apache Software Foundation Apache Tomcat, tomcat
Affected versions: 11.0.0-M1, 10.1.0-M1, 9.0.0.M1, 8.5.0, 7.0.0, < 9.0.101, >= 10.1.0 < 10.1.37, >= 11.0.0 < 11.0.5
Fixed versions: 9.0.101, 10.1.37, 11.0.5

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide

1
Identify
Confirm that Apache Software Foundation Apache Tomcat, tomcat and an affected version are present.
2
Prioritize
Combine exploitation signals with asset exposure and business criticality.
3
Remediate
Follow the vendor advisory or supported update path and preserve rollback options.
4
Verify
Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
CWE: CWE-304