CVE-2026-111816: CWE-444 Inconsistent Interpretation of HTTP Requests in Apache Software Foundation Apache Traffic Server
Description
CVE-2026-111816 is a critical vulnerability in Apache Traffic Server that allows cache poisoning and response-framing desynchronization due to inconsistent interpretation of malformed HTTP 302 responses involving Transfer-Encoding: chunked. This affects versions 8.0.0 through 8.1.11, 9.0.0 through 9.2.15, 10.0.0 through 10.1.4, and exactly 10.2.0. Fixed versions include 9.2.16, 10.1.5, and 10.2.1.
CVSS v3.1
Score 9.3critical
Affected software
Apache Software Foundation
Apache Traffic Server
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
Apache Traffic Server improperly forwards malformed HTTP 302 responses that should have been rejected as parse errors. The issue arises because the Transfer-Encoding: chunked carve-out bypasses the rejection path, causing peers to interpret the response differently. This inconsistency leads to storing and serving responses that enable cache poisoning and response-framing desynchronization attacks. The vulnerability affects multiple version ranges from 8.0.0 to 10.2.0 and is addressed in subsequent patch releases.
Potential Impact
An attacker can exploit this vulnerability to poison the cache and cause response-framing desynchronization, potentially leading to high integrity impact by serving malicious or manipulated content to users. Confidentiality impact is low, and availability is not affected. The vulnerability has a CVSS 3.1 score of 9.3, indicating critical severity.
Mitigation Recommendations
Users should upgrade Apache Traffic Server to versions 9.2.16, 10.1.5, or 10.2.1 or later, where this issue is fixed. No other mitigations are specified or recommended by the vendor.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- apache
- Date Reserved
- 2026-10-16T20:25:17.923Z
- Cvss Version
- 3.1
- State
- PUBLISHED
Threat ID: 6ad908764d27ba8daadfcd58
Added to database: 10/21/2026, 18:46:14 UTC
Last enriched: 10/21/2026, 19:00:20 UTC
Last updated: 10/21/2026, 19:01:10 UTC
Views: 6
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