Description
Apache Traffic Server can return an origin connection to the shared pool while the origin is still waiting on a request body the client declared but never fully sent, including when the client used Expect: 100-continue. The origin then reads a later request on that connection as leftover body data, which lets an attacker smuggle requests past ATS access controls, disrupt other users' requests, or poison the cache.



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.
Published: 2026-10-21
Score: 9.1 Critical
EPSS: n/a
KEV: No
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Remediation

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History

Wed, 21 Oct 2026 18:30:00 +0000

Type Values Removed Values Added
Description Apache Traffic Server can return an origin connection to the shared pool while the origin is still waiting on a request body the client declared but never fully sent, including when the client used Expect: 100-continue. The origin then reads a later request on that connection as leftover body data, which lets an attacker smuggle requests past ATS access controls, disrupt other users' requests, or poison the cache. 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.
Title Apache Traffic Server: Origin connection still owed a request body is reused, enabling request smuggling
Weaknesses CWE-444
References
Metrics cvssV3_1

{'score': 8.9, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:L'}

cvssV4_0

{'score': 9.1, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:H/VA:L/SC:H/SI:H/SA:L'}

Subscriptions

No data.

cve-icon MITRE

Status: PUBLISHED

Assigner: apache

Published:

Updated: 2026-10-21T18:22:28.383Z

Reserved: 2025-04-01T00:04:31.777Z

Link: CVE-2025-31699

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-10-21T19:16:47.390

Modified: 2026-10-21T19:16:47.390

Link: CVE-2025-31699

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-10-21T21:30:15Z

Weaknesses
  • CWE-444

    Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')