CVE-2025-31699CWE-444

CVE-2025-31699

High · published October 21, 2026

CVSS v3.1
8.9
EPSS
0%
Percentile
17.5
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
8.9 · HIGH
Vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:L
CVSS v4.0
9.1 · 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
EPSS
0.00266 · 17.5th percentile
Weakness
CWE-444 · Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')
Published
2026-10-21T23:16Z
References (1)
https://lists.apache.org/thread/r95dq29ywcd1f4x30snxlqmb12z4s4kc · [email protected]
EPSS history
Timeline
  • 23 OCT 03:49Z
    EPSS moved — → 0%
    epss
  • 21 OCT 18:22Z
    Apache Traffic Server: Origin connection still owed a request body is reused, enabling request smuggling
    cvelistv5
  • 21 OCT 18:22Z
    Apache Traffic Server: Origin connection still owed a request body is reused, enabling request smuggling
    cvelistv5