CVE-2017-5651 Expected Behavior Violation in Apache Tomcat

What is CVE-2017-5651?

CVE-2017-5651 is a critical vulnerability in Apache Tomcat, published on 17 Apr 2017. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

In Apache Tomcat 9.0.0.M1 to 9.0.0.M18 and 8.5.0 to 8.5.12, the refactoring of the HTTP connectors introduced a regression in the send file processing. If the send file processing completed quickly, it was possible for the Processor to be added to the processor cache twice. This could result in the same Processor being used for multiple requests which in turn could lead to unexpected errors and/or response mix-up.

Which versions are affected by CVE-2017-5651?

8 open source packages ship an affected version, including org.apache.tomcat.embed:tomcat-embed-core and org.apache.tomcat:tomcat-coyote. It affects 1 product.

Products include Apache Tomcat.

How do I fix CVE-2017-5651?

Upgrade org.apache.tomcat.embed:tomcat-embed-core to a fixed version for your release line: 8.5.13 or 9.0.0.M19.

Is CVE-2017-5651 being exploited?

There is no known exploitation of CVE-2017-5651 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 GHSA-9hg2-395j-83rm.