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Vulnerability record · CVE-2026-33515 · published 26 March 2026

CVE-2026-33515: Squid-cache squid out-of-bounds read vulnerability

Squid Cache · Squid

Squid is a caching proxy for the Web. Prior to version 7.5, due to improper input validation, Squid is vulnerable to out of bounds read when handling ICP traffic. This problem allows a remote attacker to receive small amounts of memory potentially containing sensitive information when responding with errors to invalid ICP requests. 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.

6.9 CVSS 4.0 Medium EPSS 2.2% · top 18.1% CWE-125 · Out-of-bounds readCWE-1289 · CWE-1289
6.9CVSS 4.0 base score
2.2%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
5References
17 Jun 2026Last modified by NVD

Description

Squid is a caching proxy for the Web. Prior to version 7.5, due to improper input validation, Squid is vulnerable to out of bounds read when handling ICP traffic. This problem allows a remote attacker to receive small amounts of memory potentially containing sensitive information when responding with errors to invalid ICP requests. 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:L/VI:L/VA:N/SC:L/SI:N/SA:N/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:

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://github.com/squid-cache/squid/commit/8138e909d2058d4401e0ad49b583afaec912b165 Patch
https://github.com/squid-cache/squid/pull/2220 Issue Tracking
https://github.com/squid-cache/squid/pull/2220#discussion_r2727683637 Issue Tracking
https://github.com/squid-cache/squid/security/advisories/GHSA-84p4-hcx7-jj7c Vendor Advisory
http://www.openwall.com/lists/oss-security/2026/03/25/4 Mailing ListThird Party Advisory

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

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Source: NIST National Vulnerability Database (record CVE-2026-33515), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.