CVE-2026-111809

Critical

Description

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.

SeverityCritical

CVSS9.3

Exploit probability—

Product

Apache Traffic Server

PublishedOct 21, 2026

First seenOct 21, 2026

Weakness typeCWE-444CWE-444

How to fix

Vendor advisories

lists.apache.org/thread/r95dq29ywcd1f4x30snxlqmb12z4s4kc

Affected products

Product	Affected versions	Fixed in
Apache Software Foundation Apache Traffic Server	8.0.0 ≤ v ≤ 8.1.11, 9.0.0 ≤ v ≤ 9.2.15, 10.0.0 ≤ v ≤ 10.1.4, 10.2.0	—

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