high7.5
CVE-2026-33526
Squid is a caching proxy for the Web.
Impact
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.
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Squid-Cache | Squid | before 7.5 |
Weakness classification
References
- NVD record
- CVE.org record
- https://github.com/squid-cache/squid/commit/8a7d42f9d44befb8fcbbb619505587c8de6a1e91
- https://github.com/squid-cache/squid/security/advisories/GHSA-hpfx-h48q-gvwg
- http://www.openwall.com/lists/oss-security/2026/03/25/2
- https://access.redhat.com/errata/RHSA-2026:10255
- https://access.redhat.com/errata/RHSA-2026:10256
- https://access.redhat.com/errata/RHSA-2026:10257
- https://access.redhat.com/errata/RHSA-2026:11901
- https://access.redhat.com/errata/RHSA-2026:20564
- https://access.redhat.com/errata/RHSA-2026:20565
- https://access.redhat.com/errata/RHSA-2026:20580
- https://access.redhat.com/errata/RHSA-2026:6301
- https://access.redhat.com/errata/RHSA-2026:8119
- https://access.redhat.com/errata/RHSA-2026:8317
- https://access.redhat.com/errata/RHSA-2026:8880
- https://access.redhat.com/errata/RHSA-2026:9220
- https://access.redhat.com/security/cve/CVE-2026-33526
- https://bugzilla.redhat.com/show_bug.cgi?id=2451574
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-33526.json