Squid is a caching proxy for the Web. Prior to version 7.5, due to premature release of resource during expected lifetime and heap Use-After-Free bugs, Squid is vulnerable to Denial of Service when handling ICP traffic. This problem allows a remote attacker to perform a reliable and repeatable Denial of Service attack against the Squid service using ICP protocol. This attack is limited to Squid deployments that explicitly enable ICP support (i.e. configure non-zero `icp_port`). This problem _cannot_ be mitigated by denying ICP queries using `icp_access` rules. This bug is fixed in Squid version 7.5.

NOTE: https://www.openwall.com/lists/oss-security/2026/03/25/3
NOTE: Fixed by: https://github.com/squid-cache/squid/commit/703e07d25ca6fa11f52d20bf0bb879e22ab7481b (SQUID_7_5)