Incorrect Comparison in Apache Traffic Server - CVE-2026-41920

Vulnerability identifier: #VU144771

CSH Severity: High

CVSS v4: 9.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-41920

CWE-ID: CWE-697

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote attacker to bypass host-SNI policy.

The vulnerability exists due to incorrect string comparison in TLS/SNI when comparing the TLS SNI against the Host header using a length taken from the Host alone. A remote attacker can send a specially crafted SNI value to bypass host-SNI policy.

Any SNI value that has the Host header as a prefix can trigger the issue.

Apache Traffic Server
Fedora
openEuler
trafficserver
trafficserver-perl
trafficserver-devel
trafficserver-debugsource
trafficserver-debuginfo

Install security update from vendor's website.

Apache Traffic Server - addressed in versions 9.2.14, 10.1.3
trafficserver - update to 9.2.15-1
trafficserver-perl - update to 9.2.15-1
trafficserver-devel - update to 9.2.15-1
trafficserver-debugsource - update to 9.2.15-1
trafficserver-debuginfo - update to 9.2.15-1
trafficserver - addressed in versions 9.2.15-1.el8, 9.2.15-1.el9, 10.1.4-1.fc43, 10.1.4-1.fc44

• https://lists.apache.org/api/email.lua?id=ckg7ohx9lb7bfs49yyyd9cwd1zctffgc
• https://gitbox.apache.org/repos/asf/trafficserver-site.git

• Multiple vulnerabilities in Apache Traffic Server
• Fedora EPEL 8 update for trafficserver
• Fedora EPEL 9 update for trafficserver
• Fedora 44 update for trafficserver
• Fedora 43 update for trafficserver
• openEuler 24.03 LTS SP1 update for trafficserver
• openEuler 24.03 LTS SP4 update for trafficserver
• openEuler 24.03 LTS SP3 update for trafficserver