CVE-2019-17569 Potential HTTP request smuggling in Apache Tomcat

What is CVE-2019-17569?

CVE-2019-17569 is a medium-severity vulnerability in Apache Tomcat, published on 24 Feb 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

The refactoring present in Apache Tomcat 9.0.28 to 9.0.30, 8.5.48 to 8.5.50 and 7.0.98 to 7.0.99 introduced a regression. The result of the regression was that invalid Transfer-Encoding headers were incorrectly processed leading to a possibility of HTTP Request Smuggling if Tomcat was located behind a reverse proxy that incorrectly handled the invalid Transfer-Encoding header in a particular manner. Such a reverse proxy is considered unlikely.

Weakness: CWE-444

Which versions are affected by CVE-2019-17569?

12 open source packages ship an affected version, including org.apache.tomcat.embed:tomcat-embed-core and org.apache.tomcat:tomcat. It affects 16 products.

Products include Apache Tomcat, Apache Tomee, Debian Debian Linux, Netapp Data Availability Services, Netapp Oncommand System Manager, Opensuse Leap and 10 more.

How do I fix CVE-2019-17569?

Upgrade org.apache.tomcat.embed:tomcat-embed-core to a fixed version for your release line: 7.0.100, 8.5.51 or 9.0.31.

Is CVE-2019-17569 being exploited?

There is no known exploitation of CVE-2019-17569 in the wild and no public exploit code.

Other vulnerabilities in Apache Tomcat

• CVE-2025-24813 Apache Tomcat Path Equivalence Exploited Critical 10.0
• CVE-2016-8735 Apache Tomcat Remote Code Execution Exploited Critical 9.8
• CVE-2017-12617 Apache Tomcat Remote Code Execution Exploited High 8.1
• CVE-2017-12615 Apache Tomcat on Windows Remote Code Execution Exploited High 8.1
• CVE-2026-34486 Apache Tomcat Missing Encryption of Sensitive Data Exploited High 7.5

All Apache Tomcat vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as DEBIAN-CVE-2019-17569, GHSA-767j-jfh2-jvrc.