CVE-2025-31699: CWE-444 Inconsistent Interpretation of HTTP Requests in Apache Software Foundation Apache Traffic Server
Description
CVE-2025-31699 is a high-severity vulnerability in Apache Traffic Server affecting versions from 8.0.0 through 8.1.11, 9.0.0 through 9.2.15, 10.0.0 through 10.1.4, and version 10.2.0. The issue arises when the server returns an origin connection to the shared pool while the origin is still waiting on a request body that the client declared but never fully sent, including cases involving the Expect: 100-continue header. This can cause the origin to misinterpret subsequent requests as leftover body data, enabling request smuggling past access controls, disruption of other users' requests, or cache poisoning. Fixed versions include 9.2.16, 10.1.5, and 10.2.1.
CVSS v3.1
Score 8.9high
Affected software
Apache Software Foundation
Apache Traffic Server
pkg:maven/org.apache.trafficserver/trafficserverRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
Apache Traffic Server improperly handles HTTP requests when a client declares a request body but does not fully send it, including when using the Expect: 100-continue header. The server returns the origin connection to the shared pool prematurely, causing the origin to read subsequent requests as leftover body data. This inconsistent interpretation of HTTP requests (CWE-444) allows attackers to smuggle requests past ATS access controls, disrupt other users' requests, or poison the cache. The vulnerability affects multiple version ranges from 8.0.0 to 10.2.0 and is addressed by upgrading to versions 9.2.16, 10.1.5, or 10.2.1.
Potential Impact
An attacker can exploit this vulnerability to bypass access controls by smuggling HTTP requests, disrupt legitimate user requests, or poison the cache, potentially leading to unauthorized access, denial of service, or serving of malicious cached content. The CVSS 3.1 score is 8.9 (high), indicating a network attack vector with high impact on confidentiality and integrity, and low impact on availability.
Mitigation Recommendations
Users should upgrade Apache Traffic Server to versions 9.2.16, 10.1.5, or 10.2.1, which contain the official fixes for this vulnerability. No alternative mitigations are indicated in the advisory.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- apache
- Date Reserved
- 2025-04-01T00:04:31.777Z
- Cvss Version
- 3.1
- State
- PUBLISHED
Threat ID: 6ad9050d4d27ba8daadc99a0
Added to database: 10/21/2026, 18:31:41 UTC
Last enriched: 10/21/2026, 19:00:28 UTC
Last updated: 10/21/2026, 19:00:28 UTC
Views: 7
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