CVE-2026-86350

Critical

Description

Inconsistent interpretation of HTTP/2 requests ('HTTP Request/Response smuggling') vulnerability in Apache Tomcat caused by a regression in fix for CVE-2026-41293 can trigger request header mix-up. This issue affects Apache Tomcat: from 11.0.22 through 11.0.25, from 10.1.55 through 10.1.59, from 9.0.118 through 9.0.121. Users are recommended to upgrade to version 11.0.26, 10.1.60 or 9.0.122, which fix the issue.

SeverityCritical

CVSS9.1

Exploit probability—

Product

Apache Tomcat

PublishedSep 23, 2026

First seenSep 23, 2026

Weakness typeCWE-444CWE-444

How to fix

Vendor advisories

lists.apache.org/thread/mss45z99lcdd5dtpgcn45dy82f3toswc

Affected products

Product	Affected versions	Fixed in
Apache Software Foundation Apache Tomcat	11.0.22 ≤ v ≤ 11.0.25, 10.1.55 ≤ v ≤ 10.1.59, 9.0.118 ≤ v ≤ 9.0.121	—

Check your version

Choose the product and enter the version you run to see whether it falls in the affected range.

In the Intelligence 360 plan

Attack Surface Management

See the assets tied to your domains, the technologies they run and known vulnerabilities in one list.