Authentication Bypass in Apache Tomcat WebSocket Endpoints
CVE-2026-76183

9.8CRITICAL

Key Information:

Vendor

Apache
Status
Apache Tomcat
Vendor
CVE Published:
23 September 2026

What is CVE-2026-76183?

An authentication bypass vulnerability exists in Apache Tomcat that allows attackers to circumvent security constraints for WebSocket endpoints. This flaw affects multiple versions of Apache Tomcat, allowing unauthorized access and control over user sessions. To mitigate this risk, users should upgrade to Apache Tomcat versions 11.0.26, 10.1.60, or 9.0.122, which address the identified vulnerabilities.

Affected Version(s)

Apache Tomcat 11.0.0-M1 <= 11.0.25

Apache Tomcat 10.1.0-M1 <= 10.1.59

Apache Tomcat 9.0.0.M1 <= 9.0.121

References

https://lists.apache.org/thread/45mxk8nj2q8pkhct6lfxkvtm2...
vendor-advisory

CVSS V3.1

Score:
9.8
Severity:
CRITICAL
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

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