Vulnerability 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.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Squid-Cache | Squid | < 7.5 |
Related Weaknesses (CWE)
References
- https://github.com/squid-cache/squid/commit/8a7d42f9d44befb8fcbbb619505587c8de6aPatch
- https://github.com/squid-cache/squid/security/advisories/GHSA-hpfx-h48q-gvwgVendor Advisory
- http://www.openwall.com/lists/oss-security/2026/03/25/2Third Party Advisory
FAQ
What is CVE-2026-33526?
CVE-2026-33526 is a vulnerability with a CVSS score of 7.5 (HIGH). 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 per...
How severe is CVE-2026-33526?
CVE-2026-33526 has been rated HIGH with a CVSS base score of 7.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-33526?
Check the references section above for vendor advisories and patch information. Affected products include: Squid-Cache Squid.