A prototype pollution vulnerability has been reported to affect several QNAP operating system versions. If exploited, the vulnerability could allow users to override existing attributes with ones that have incompatible type, which may lead to a crash via a network. We have already fixed the vulnerability in the following versions: QTS 5.1.3.2578 build 20231110 and later QuTS hero h5.1.3.2578 build 20231110 and later