CVE-2026-111808CWE-191

CVE-2026-111808

High · published October 22, 2026

CVSS v3.1
8.6
EPSS
0%
Percentile
24.3
In the wild
Unconfirmed
What it is

Apache Traffic Server can be used to exhaust an HTTP/1.1 origin's worker pool via a malformed padded HTTP/2 DATA frame.

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
8.6 · HIGH
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
CVSS v4.0
7.7 · CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:N/SI:N/SA:H
EPSS
0.00324 · 24.3th percentile
Weakness
CWE-191 · Integer Underflow (Wrap or Wraparound)
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 19:11Z
    Apache Traffic Server: HTTP/2 DATA frame padding underflow lets a client trigger backend worker-pool exhaustion
    cvelistv5
  • 21 OCT 19:11Z
    Apache Traffic Server: HTTP/2 DATA frame padding underflow lets a client trigger backend worker-pool exhaustion
    cvelistv5