Last updated 25 August 2025

It was discovered that the implementation of the PatternSyntaxException class in the Concurrency component of OpenJDK failed to sufficiently validate the 'index' value (to ensure it's not greater than the regular expression length) in the getMessage() method. An instance of the class with invalid index value, for example one created via deserialization on an untrusted input, could cause a Java application to use an excessive amount of memory.