The issue concerns two problems in the Open Enclave SDK. First, it does not properly sanitize the `MXCSR` register on enclave entry, making applications vulnerable to MXCSR Configuration Dependent Timing (MCDT) attacks. This could impact instruction retirement by at most one cycle, depending on the secret data operand value. Second, the SDK does not sanitize x86's alignment check flag `RFLAGS.AC` on enclave entry, allowing a side-channel attacker to be notified for every unaligned memory access performed by the enclave.