CVE•Published 2026-03-26•Modified 2026-07-15•0 articles on news•5 live references•NVD data

CVE-2026-33526Squid-cache · Squid

Vulnerability data via NVD (ingested)

CVSS v3.1

7.5

HIGH

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS percentile

Exploit Prediction Scoring System · top 5% of all CVEs

Weaknesses (CWE)

CWE-416Use After Free CWE-826Premature Release of Resource During Expected Lifetime CWE-825Expired Pointer Dereference

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.

Timeline

Published 2026-03-26

Modified 2026-07-15

External references

NVD MITRE Exploit-DB GitHub PoC VulnCheck

Search for exposed instances

Shodan + Censys queries derived from NVD's CPE data. The vuln tag catches assets Shodan has explicitly linked to this CVE; the product / banner fingerprints find exposed instances even when the vuln tag was never applied (which is common).

Shodan · vuln tag1,720,688 hosts

vuln:CVE-2026-33526

Hosts Shodan has explicitly fingerprinted as vulnerable.

Shodan · product

product:"Squid-cache Squid"

All exposed Squid-cache Squid instances — cross-reference with the CVE's affected-version range.

Shodan · banner/body mention

http.html:"Squid"

HTTP body or banner mentions "Squid" — catches deploys Shodan didn't identify as a product.

More intel sources (5)

Shodan report

vuln:CVE-2026-33526