The product performs the same operation on a resource two or more times, when the operation should only be applied once.
CVE-2009-0935Attacker provides invalid address to a memory-reading function, causing a mutex to be unlocked twice
CVE-2019-13351file descriptor double close can cause the wrong file to be associated with a file descriptor.
CVE-2004-1939XSS protection mechanism attempts to remove "/" that could be used to close tags, but it can be bypassed using double encoded slashes (%252F)