What is CVE-2026-111808?

CVE-2026-111808 is a high-severity vulnerability in Apache Software Foundation Traffic Server, classified under Integer Underflow. CVSS score: 8.6/10. Published 2026-10-21.

How severe is CVE-2026-111808?

High severity. CVSS v3 base score is 8.6 out of 10.

Integer overflow in Apache Software Foundation Traffic Server

CVE-2026-111808

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.

Published 2026-10-21 · last modified 2026-10-22.

CVSS v3 metric

CVSS v3 base score 8.6 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H.

EPSS exploit prediction

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Affected products

Apache Software Foundation Traffic Server — versions 10.2.0

Weakness classification (CWE)

CWE-191 — Integer Underflow

References

lists.apache.org/thread/r95dq29ywcd1f4x30snxlqmb12z4s4kc (vendor-advisory)

Frequently asked questions

What is CVE-2026-111808?: CVE-2026-111808 is a high-severity vulnerability in Apache Software Foundation Traffic Server, classified under Integer Underflow. CVSS score: 8.6/10. Published 2026-10-21.
How severe is CVE-2026-111808?: High severity. CVSS v3 base score is 8.6 out of 10.