Authentication Bypass by Capture-replay in Apache Tomcat - CVE-2026-55955
Published: June 30, 2026
Vulnerability identifier: #VU135863
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-55955
CWE-ID: CWE-294
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Apache Foundation
Affected software:
Apache Tomcat
Apache Tomcat
Detailed vulnerability description
The vulnerability allows a remote attacker to replay protected communications.
The vulnerability exists due to missing replay protection in EncryptInterceptor when processing encrypted messages. A remote attacker can capture and resend previously valid messages to replay protected communications.
How to mitigate CVE-2026-55955
Install security update from vendor's website.
Sources
- https://tomcat.apache.org/security-10.html#Fixed_in_Apache_Tomcat_10.1.56
- https://tomcat.apache.org/security-11.html#Fixed_in_Apache_Tomcat_11.0.23
- https://tomcat.apache.org/security-9.html#Fixed_in_Apache_Tomcat_9.0.119
- https://github.com/apache/tomcat/commit/3a9ff01d2dfaca651edacbda3260e37b98b540d3