Amazon Linux 2 Security Advisory: ALAS2-2026-3242
Advisory Released Date: 2026-04-14
Advisory Updated Date: 2026-04-14
Squid is a caching proxy for the Web. Prior to version 7.5, due to premature release of resource during expected lifetime and heap Use-After-Free bugs, 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. This bug is fixed in Squid version 7.5.
NOTE: https://www.openwall.com/lists/oss-security/2026/03/25/3
NOTE: Fixed by: https://github.com/squid-cache/squid/commit/703e07d25ca6fa11f52d20bf0bb879e22ab7481b (SQUID_7_5) (CVE-2026-32748)
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.
NOTE: https://www.openwall.com/lists/oss-security/2026/03/25/2
NOTE: Fixed by: https://github.com/squid-cache/squid/commit/8a7d42f9d44befb8fcbbb619505587c8de6a1e91 (SQUID_7_5) (CVE-2026-33526)
Affected Packages:
squid
Note:
This advisory is applicable to Amazon Linux 2 (AL2) Core repository. Visit this FAQ section for the difference between AL2 Core and AL2 Extras advisories.
Issue Correction:
Run yum update squid or yum update --advisory ALAS2-2026-3242 to update your system.
aarch64:
squid-3.5.20-17.amzn2.7.26.aarch64
squid-sysvinit-3.5.20-17.amzn2.7.26.aarch64
squid-migration-script-3.5.20-17.amzn2.7.26.aarch64
squid-debuginfo-3.5.20-17.amzn2.7.26.aarch64
i686:
squid-3.5.20-17.amzn2.7.26.i686
squid-sysvinit-3.5.20-17.amzn2.7.26.i686
squid-migration-script-3.5.20-17.amzn2.7.26.i686
squid-debuginfo-3.5.20-17.amzn2.7.26.i686
src:
squid-3.5.20-17.amzn2.7.26.src
x86_64:
squid-3.5.20-17.amzn2.7.26.x86_64
squid-sysvinit-3.5.20-17.amzn2.7.26.x86_64
squid-migration-script-3.5.20-17.amzn2.7.26.x86_64
squid-debuginfo-3.5.20-17.amzn2.7.26.x86_64