Home

Description

Squid is a caching proxy for the Web. Prior to version 7.5, due to heap Use-After-Free, 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. Version 7.5 contains a patch.

PUBLISHED Reserved 2026-03-20 | Published 2026-03-26 | Updated 2026-03-26 | Assigner GitHub_M




CRITICAL: 9.2CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H

Problem types

CWE-416: Use After Free

CWE-826: Premature Release of Resource During Expected Lifetime

Product status

< 7.5
affected

References

www.openwall.com/lists/oss-security/2026/03/25/2

github.com/.../squid/security/advisories/GHSA-hpfx-h48q-gvwg

github.com/...ommit/8a7d42f9d44befb8fcbbb619505587c8de6a1e91

cve.org (CVE-2026-33526)

nvd.nist.gov (CVE-2026-33526)

Download JSON