A deserialization flaw was discovered in Apache Tomcat"s use of a FileStore. Under specific circumstances, an attacker can use a specially crafted request to trigger Remote Code Execution through deserialization of the file under their control. The highest threat from the vulnerability is to data confidentiality and integrity as well as system availability. When responding to new h2c connection requests, Apache Tomcat versions 10.0.0-M1 to 10.0.0, 9.0.0.M1 to 9.0.41 and 8.5.0 to 8.5.61 could duplicate request headers and a limited amount of request body from one request to another meaning user A and user B could both see the results of user A"s request