Trusted execution environments (TEEs) like Confidential Compute from Nvidia, SEV-SNP from AMD, and SGX/TDX from Intel are integral to various industries, especially in cloud services and sensitive computing scenarios. These TEEs promise to protect confidential data and computing processes, even if the operating system kernel is compromised. However, recent developments challenge these assurances, particularly a new attack named TEE.fail. TEE.fail, introduced recently, is a physical attack that undermines the security of all three major TEEs. The attack requires minimal investment and complexity, involving a small piece of hardware placed between a memory chip and its motherboard slot. It also necessitates that the attacker has already compromised the OS kernel. Once executed, the attack takes only three minutes to disable the reliability of Confidential Compute, SEV-SNP, and TDX/SDX, making them untrustworthy. Unlike previous attacks like Battering RAM and Wiretap, which targeted older DDR4 memory, TEE.fail is effective against the newer DDR5 memory, broadening its impact on the latest security measures. The chipmakers themselves do not include physical attacks in their threat models for TEEs. Their focus is on protecting data from unauthorized access or tampering, despite the operating system being compromised. This omission isn’t clearly communicated, leading to potential misconceptions about the extent of security that these TEEs can provide.