CVE-2026-33526
critical · 9.2Squid 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.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Weaknesses
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| squid-cache | squid | < 7.5 |
Check a specific version with /api/v1/cve/match.
References
- 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
Query this programmatically:
curl https://evil-db.io/api/v1/cve/CVE-2026-33526