CVE-2026-111809CWE-444

CVE-2026-111809

Critical · published October 22, 2026

CVSS v3.1
9.3
EPSS
0%
Percentile
11.6
In the wild
Unconfirmed
What it is

Apache Traffic Server allows request smuggling via HEAD requests that carry Content-Length or Transfer-Encoding.

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
9.3 · CRITICAL
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:H/A:N
CVSS v4.0
6.9 · CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:L/SI:H/SA:N
EPSS
0.00218 · 11.6th percentile
Weakness
CWE-444 · Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')
Published
2026-10-22T00:17Z
References (1)
https://lists.apache.org/thread/r95dq29ywcd1f4x30snxlqmb12z4s4kc · [email protected]
EPSS history
Timeline
  • 23 OCT 03:55Z
    EPSS moved — → 0%
    epss
  • 21 OCT 19:16Z
    Apache Traffic Server: HEAD requests carrying Content-Length or Transfer-Encoding enable request smuggling
    cvelistv5
  • 21 OCT 19:16Z
    Apache Traffic Server: HEAD requests carrying Content-Length or Transfer-Encoding enable request smuggling
    cvelistv5