What’s Vulnerable › Vulnerabilities
CVE-2025-55702: Apache Traffic Server: An unread Expect: 100-continue request body is framed as a new request
- Severity: high (CVSS 8.7 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.3% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2026-10-21 · updated 2026-10-28
- Weakness: CWE-444
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 products
- Apache Software Foundation 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
References
Get alerted when CVE-2025-55702 or the next vulnerability affects your stack