Vulnerability · Published Oct 21, 2026 · Assigned by apache
CVE-2025-55702Apache Traffic Server: An unread Expect: 100-continue request body is framed as a new request
High 8.7
In plain English
A high-severity security flaw in Apache Traffic Server from Apache Software Foundation. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 26% of all known vulnerabilities).
Official description
When a client sends a POST with Expect: 100-continue and the origin answers before reading the body, Apache Traffic Server parses the unread body left on the client connection as the next request. An attacker behind a front-end proxy that shares connections to Traffic Server can use this to smuggle requests past the front end and desynchronize responses for other users. This issue affects Apache Traffic Server: from 8.0.0 through 8.1.11, from 9.0.0 through 9.2.15, from 10.0.0 through 10.1.4, 10.2.0. Users are recommended to upgrade to version 9.2.16, 10.1.5, or 10.2.1, which fix the issue.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | trafficserver | no fix listed | DEBIAN-CVE-2025-55702 |
| Ubuntu:24.04:LTS | trafficserver | no fix listed | UBUNTU-CVE-2025-55702 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Apache Software Foundation | Apache Traffic Server | 8.0.0 – through 8.1.119.0.0 – through 9.2.1510.0.0 – through 10.1.410.2.0 |
Weakness: CWE-444 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:N
References
- https://lists.apache.org/thread/r95dq29ywcd1f4x30snxlqmb12z4s4kc vendor-advisory