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.

Attack Vector Network

Attack Complexity Low

Privileges Required None

Attack Requirements Present

User Interaction None

Vulnerable System Confidentiality Impact Low

Vulnerable System Integrity Impact High

Vulnerable System Availability Impact Low

Subsequent System Confidentiality Impact High

Subsequent System Integrity Impact High

Subsequent System Availability Impact Low

Attack Vector Network

Attack Complexity High

Privileges Required None

Scope Changed

Confidentiality Impact High

Integrity Impact High

Availability Impact Low

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Key SSVC decision points have not yet been added.

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions
Apache Software Foundation Apache Traffic Server unaffected
Version Status Constraints
8.0.0 affected ≤ 8.1.11
9.0.0 affected ≤ 9.2.15
10.0.0 affected ≤ 10.1.4
10.2.0 affected —

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Project Subscriptions

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Advisories

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Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
https://lists.apache.org/thread/r95dq29ywcd1f4x30snxlqmb12z4s4kc cve-icon cve-icon
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'}

Projects

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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