CVE-2025-31699

critical

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.

References

https://lists.apache.org/thread/r95dq29ywcd1f4x30snxlqmb12z4s4kc

https://euvd.enisa.europa.eu/vulnerability/EUVD-2025-211167

Details

Source: Mitre, NVD

Published: 2026-10-21

Updated: 2026-10-21

Risk Information

CVSS v2

Base Score: 7.3

Vector: CVSS2#AV:N/AC:H/Au:N/C:C/I:C/A:P

Severity: High

CVSS v3

Base Score: 8.9

Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:L

Severity: High

CVSS v4

Base 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

Severity: Critical