CVE-2026-33515

Description

Squid is a caching proxy for the Web. Prior to version 7.5, due to improper input validation, Squid is vulnerable to out of bounds read when handling ICP traffic. This problem allows a remote attacker to receive small amounts of memory potentially containing sensitive information when responding with errors to invalid ICP requests. 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. Version 7.5 contains a patch.

References

• https://github.com/squid-cache/squid/commit/8138e909d2058d4401e0ad49b583afaec912b165
• https://github.com/squid-cache/squid/pull/2220
• https://github.com/squid-cache/squid/pull/2220#discussion_r2727683637
• https://github.com/squid-cache/squid/security/advisories/GHSA-84p4-hcx7-jj7c
• http://www.openwall.com/lists/oss-security/2026/03/25/4