Disclosed herein are systems and methods for identifying and mitigating Flush-based cache attacks. The systems and methods can include adding a zombie bit to a cache line. The zombie bit can be used to track the status of cache hits and misses to the flushed line. A line that is invalidated due to a Flush-Caused Invalidation can be marked as a zombie line by marking the zombie bit as valid. If another hit, or access request, is made to the cache line, data retrieved from memory can be analyzed to determine if the hit is benign or is a potential attack. If the retrieved data is the same as the cache data, then the line can be marked as a valid zombie line. Any subsequent hit to the valid zombie line can be marked as a potential attack. Hardware- and software-based mitigation protocols are also described.