---
id: CVE-2025-31699
title: >-
  Apache Traffic Server: Origin connection still owed a request body is reused,
  enabling request smuggling
summary: >-
  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 r…
severity: high
cvss: 8.9
cvssVector: 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:L'
cvssSource: cna
cwe:
  - CWE-444
vendor: Apache Software Foundation
product: Apache Traffic Server
affected:
  - apache_traffic_server >= 8.0.0 <= 8.1.11
  - apache_traffic_server >= 9.0.0 <= 9.2.15
  - apache_traffic_server >= 10.0.0 <= 10.1.4
  - apache_traffic_server 10.2.0
published: '2026-10-21'
updated: '2026-10-21'
sourceUpdated: '2026-10-21T18:22:28.383Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2025-31699'
references:
  - url: 'https://lists.apache.org/thread/r95dq29ywcd1f4x30snxlqmb12z4s4kc'
tags:
  - cve.org
ingestedAt: '2026-10-21T19:10:31.401Z'
---

## Overview

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.

## Affected

- `apache_traffic_server >= 8.0.0 <= 8.1.11`
- `apache_traffic_server >= 9.0.0 <= 9.2.15`
- `apache_traffic_server >= 10.0.0 <= 10.1.4`
- `apache_traffic_server 10.2.0`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.