CVE-2016-2570: Squid-Cache Squid

High severity, CVSS 7.5. EPSS: 9% chance of exploitation in the next 30 days.

The Edge Side Includes (ESI) parser in Squid 3.x before 3.5.15 and 4.x before 4.0.7 does not check buffer limits during XML parsing, which allows remote HTTP servers to cause a denial of service (assertion failure and daemon exit) via a crafted XML document, related to esi/CustomParser.cc and esi/CustomParser.h.

Affected products

• Squid-Cache Squid: version 3.0 only; version 3.0.stable1 only; version 3.0.stable2 only; version 3.0.stable3 only; version 3.0.stable4 only; version 3.0.stable5 only; …

Published 2016-02-27. Last modified 2026-06-17.