CVE-2025-55702: 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
CVE-2025-55702 key facts
- CISA KEV
- Not listed (catalogue checked )
- Highest advisory rating
- High
- CVSS base score
- 8.7 (Red Hat), 7 (Apache)
- Weakness
- CWE-444
- Fixed releases
- Apache: 9.2.16, 10.1.5, 10.2.1
- Red Hat: 9.2.16, 10.1.5, 10.2.1
- Listed by VulniPulse
- Record changed
Ratings, versions and fixes are quoted from the vendor advisories that cover only CVE-2025-55702; each belongs to its advisory, not to every product listed. How records are collected and checked.
How do I fix CVE-2025-55702?
Upgrade to a fixed release named by the vendor:
- Apache: 9.2.16, 10.1.5, 10.2.1
- Red Hat: 9.2.16, 10.1.5, 10.2.1
- Users are recommended to upgrade to version 9.2.16, 10.1.5, or 10.2.1, which fix the issue. (Apache)
Vendor advisories for CVE-2025-55702
Apache
1 advisory- Advisory severityHigh7.0
High [CVE-2025-55702] 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
CVE-2025-55702Source published Source updated
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 in this advisory
- Apache Traffic Server
- Source-reported affected versions
- 8.0.0 through 8.1.11
- 9.0.0 through 9.2.15
- 10.0.0 through 10.1.4
- Source-reported fixed versions
- 9.2.16
- 10.1.5
- 10.2.1
- Mitigation guidance
- Users are recommended to upgrade to version 9.2.16, 10.1.5, or 10.2.1, which fix the issue.
Red Hat
1 advisory- Advisory severityHigh8.7
High [CVE-2025-55702] HTTP request smuggling via unread POST request body
CVE-2025-55702Source published Source updated
HTTP request smuggling via unread POST request body. Red Hat rates this important (CVSS 8.7). Weakness: CWE-444.
- Related products — impact not confirmed
- No product details extracted. Check the source bulletin.
- Source-reported affected versions
- 8.0.0
- 8.1.11
- 9.0.0
- 9.2.15
3 more entries in the full advisory.
- Source-reported fixed versions
- 9.2.16
- 10.1.5
- 10.2.1
- Mitigation guidance
- No mitigation guidance extracted; consult the source.
References
More Apache advisories
CVE-2026-112381Oct 21, 2026Apache Traffic Server can crash with a null pointer dereferenceCVE-2026-111817Oct 21, 2026Apache Traffic Server can stall a chunked transferCVE-2026-111812Oct 21, 2026Apache Traffic Server's origin_server_auth plugin lets a client force signingCVE-2026-111811Oct 21, 2026Apache Traffic Server's experimental tsmemcache pluginCVE-2026-111809Oct 21, 2026Apache Traffic ServerCVE-2026-111810Oct 21, 2026Apache Traffic Server 9.2.15, 10.1.4 and 10.2.0 write one unthrottled diagnostic log line
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