Improper access control in Apache Tomcat - CVE-2026-65637
Published: August 26, 2026
Vulnerability identifier: #VU145381
CSH Severity: Medium
CVSS v4: 6.9 [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]
CVE-ID: CVE-2026-65637
CWE-ID: CWE-284
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to bypass strict SNI validation.
The vulnerability exists due to improper access control in the HTTP/2 request handling when processing requests without an authority field. A remote attacker can send a specially crafted HTTP/2 request to bypass strict SNI validation.
The issue is related to an incomplete fix for a previous vulnerability.
Affected software
Apache Tomcat
How to mitigate CVE-2026-65637
Install security update from vendor's website.
Apache Tomcat - addressed in versions 9.0.121, 10.1.59, 11.0.25