Inconsistent interpretation of HTTP requests in Apache Traffic Server - CVE-2025-55702
Published: October 23, 2026
Vulnerability identifier: #VU157324
CSH Severity: High
CVSS v4: 9.1 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2025-55702
CWE-ID: CWE-444
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to smuggle requests past a front-end proxy and desynchronize responses for other users.
The vulnerability exists due to improper HTTP request framing in Apache Traffic Server when an origin responds to a POST with Expect: 100-continue before reading its body, leaving the unread body to be parsed as another request. A remote attacker can send a crafted POST through a front-end proxy that shares connections to Traffic Server to smuggle a request past the front end and desynchronize other users' responses.
Affected software
Apache Traffic Server
Fedora
trafficserver
Fedora
trafficserver
How to mitigate CVE-2025-55702
Install security update from vendor's website.
Apache Traffic Server - addressed in versions 9.2.16, 10.1.5, 10.2.1
trafficserver - addressed in versions 10.2.1-1.el10_2, 10.2.1-1.el10_3, 10.2.1-1.el10_4, 10.2.1-1.fc44, 10.2.1-1.fc45
trafficserver - addressed in versions 10.2.1-1.el10_2, 10.2.1-1.el10_3, 10.2.1-1.el10_4, 10.2.1-1.fc44, 10.2.1-1.fc45