CVE-2023-42794: Apache Tomcat

Medium severity, CVSS 5.9. EPSS: 1.9% chance of exploitation in the next 30 days.

Incomplete Cleanup vulnerability in Apache Tomcat. The internal fork of Commons FileUpload packaged with Apache Tomcat 9.0.70 through 9.0.80 and 8.5.85 through 8.5.93 included an unreleased, in progress refactoring that exposed a potential denial of service on Windows if a web application opened a stream for an uploaded file but failed to close the stream. The file would never be deleted from disk creating the possibility of an eventual denial of service due to the disk being full. Other, EOL versions may also be affected. Users are recommended to upgrade to version 9.0.81 onwards or 8.5.94 onwards, which fixes the issue.

Affected products

• Apache Tomcat: from 8.5.85, before 8.5.94 (fixed in 8.5.94); from 9.0.70, before 9.0.81 (fixed in 9.0.81)

Published 2023-10-10. Last modified 2026-10-08.