Use After Free in Squid-Cache Squid

CVE-2026-32748

Squid is a caching proxy for the Web. Prior to version 7.5, due to premature release of resource during expected lifetime and heap Use-After-Free bugs, 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. This bug is fixed in Squid version 7.5.

EPSS: 0.089 (94.9th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-32748?
CVE-2026-32748 is a high-severity vulnerability in Squid-Cache Squid, classified under CWE-413. CVSS score: 7.5/10. Published 2026-03-26.
How severe is CVE-2026-32748?
High severity. CVSS v3 base score is 7.5 out of 10.