CVE-2026-33526 identifies a heap Use-After-Free vulnerability in Squid caching proxy versions prior to 7.5, enabling a remote attacker to perform a reliable Denial of Service (DoS) attack when handling ICP traffic. This vulnerability specifically affects Squid deployments with explicitly enabled ICP support. Rated with a CVSSv3.1 score of 7.5 (HIGH), the flaw has a network attack vector and low attack complexity, leading to a complete loss of availability for affected services. There is currently no evidence of active exploitation, and public exploit code is not available. While community discussion exists, the vulnerability is not listed in CISA's KEV catalog, and a patch is available in Squid version 7.5.
| Vendor | Product | Version(s) | CPE |
|---|---|---|---|
< 7.5CPE matchmatch criteria | cpe:2.3:a:squid-cache:squid:*:*:*:*:*:*:*:* |
CVSS version used by this source: 4.0
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
The average CVE in this peer group has 0.0 Twitter, 0.0 Reddit, 0.1 Bluesky, 0.1 Mastodon, and 0.4 GitHub mentions.
The average CVE in this peer group has 0.1 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.