Apache Tomcat 9/10/11 HTTP2 Request Smuggling v9.0.118-121,10.1.55-59,11.0.22-25
CVE-2026-86350 Published on September 23, 2026
Apache Tomcat: Regression in fix for CVE-2026-41293 can trigger request header mix-up
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.
Vulnerability Analysis
CVE-2026-86350 is exploitable with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have a high impact on confidentiality and integrity, and no impact on availability.
Weakness Type
What is a HTTP Request Smuggling Vulnerability?
When malformed or abnormal HTTP requests are interpreted by one or more entities in the data flow between the user and the web server, such as a proxy or firewall, they can be interpreted inconsistently, allowing the attacker to "smuggle" a request to one device without the other device being aware of it.
CVE-2026-86350 has been classified to as a HTTP Request Smuggling vulnerability or weakness.
Products Associated with CVE-2026-86350
Want to know whenever a new CVE is published for Apache Tomcat? stack.watch will email you.
Affected Versions
Apache Software Foundation Apache Tomcat:- Version 11.0.22, <= 11.0.25 is affected.
- Version 10.1.55, <= 10.1.59 is affected.
- Version 9.0.118, <= 9.0.121 is affected.