Race condition in Apache Tomcat - CVE-2026-79677
Published: September 23, 2026
Vulnerability identifier: #VU151841
CSH Severity: Medium
CVSS v4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-79677
CWE-ID: CWE-362
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to a concurrency bug in asynchronous WebSocket write handling when performing asynchronous WebSocket writes. A remote attacker can trigger lost write timeouts to cause a denial of service.
Affected software
Apache Tomcat
How to mitigate CVE-2026-79677
Install security update from vendor's website.
Apache Tomcat - addressed in versions 9.0.122, 10.1.60, 11.0.26