Race condition in Apache Tomcat - CVE-2026-77762
Published: September 23, 2026
Vulnerability identifier: #VU151845
CSH Severity: Low
CVSS v4: 6.3 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-77762
CWE-ID: CWE-362
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to inject trailer fields into another HTTP/2 request.
The vulnerability exists due to a race condition in the HPACK emitter when processing HTTP/2 requests with recycled pooled requests. A remote attacker can trigger the race condition to inject trailer fields into another HTTP/2 request.
Affected software
Apache Tomcat
How to mitigate CVE-2026-77762
Install security update from vendor's website.
Apache Tomcat - addressed in versions 9.0.122, 10.1.60, 11.0.26