[Harvesterify]

Exploited in the wild, difficult to say, but there has been numerous vulnerabilities reported on underlying technologies used for confidential computing (Intel SGX, AMD SEV, Intel TDX, for example) and quite a good amount of external research and publications on the topic.

The threat model for these technologies can also sometimes be sketchy (lack of side channel protection for Intel SGX, lack of integrity verification for AMD SEV, for example)