Out-of-bounds Read in Squid-Cache Squid
CVE-2026-33515
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.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N.
EPSS exploit prediction
EPSS: 0.022 (81.9th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 82nd percentile — 81.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.010 · newest: 0.022 · change: +0.012
Affected products
- Squid-Cache Squid — versions < 7.5
Weakness classification (CWE)
References
- github.com/squid-cache/squid/security/advisories/GHSA-84p4-hcx7-jj7c (Vendor Advisory)
- github.com/squid-cache/squid/pull/2220 (Issue Tracking)
- github.com/squid-cache/squid/pull/2220 (Issue Tracking)
- github.com/squid-cache/squid/commit/8138e909d2058d4401e0ad49b583afaec912b165 (Patch)
- af854a3a-2127-422b-91ae-364da2661108 (Mailing List, Third Party Advisory)
Frequently asked questions
- What is CVE-2026-33515?
- CVE-2026-33515 is a medium-severity vulnerability in Squid-Cache Squid, classified under Out-of-bounds Read. CVSS score: 6.5/10. Published 2026-03-26.
- How severe is CVE-2026-33515?
- Medium severity. CVSS v3 base score is 6.5 out of 10.