A single-byte, non-arbitrary write/use-after-free flaw was found in dnsmasq, allowing an attacker to potentially cause a denial of service by sending a crafted packet processed by dnsmasq. The flaw is related to an error in memory usage after it has been freed, specifically in the processing of DHCPv6 requests. This can be exploited by a remote attacker to send specially crafted packets, causing a use-after-free error and resulting in a denial of service attack.