SB20260325206 - Multiple vulnerabilities in Squid ICP feature

Description

This security bulletin contains information about 3 secuirty vulnerabilities.

1) Use After Free (CVE-ID: CVE-2026-32748)

The vulnerability allows a remote attacker to cause a denial of service.

The vulnerability exists due to use-after-free in ICP request handling when processing ICP traffic. A remote attacker can send a specially crafted ICP request to cause a denial of service.

The vulnerability is only exploitable on Squid deployments that have ICP support enabled via a non-zero icp_port configuration.

2) Out-of-bounds read (CVE-ID: CVE-2026-33515)

The vulnerability allows a remote attacker to disclose sensitive information.

The vulnerability exists due to improper input validation in ICP message handling when processing ICP traffic. A remote attacker can send a specially crafted ICP request to disclose small amounts of memory potentially containing sensitive information.

The attack is limited to Squid deployments that explicitly enable ICP support (i.e., configure a non-zero icp_port).

3) Use After Free (CVE-ID: CVE-2026-33526)

The vulnerability allows a remote attacker to cause a denial of service.

The vulnerability exists due to heap use-after-free in ICP request handling when processing ICP traffic. A remote attacker can send a specially crafted ICP request to cause a denial of service.

The attack is limited to Squid deployments that have ICP support enabled via a non-zero icp_port configuration.

Remediation

Install update from vendor's website.

References

• https://github.com/squid-cache/squid/security/advisories/GHSA-f9p7-3jqg-hhvq
• https://github.com/squid-cache/squid/security/advisories/GHSA-84p4-hcx7-jj7c
• https://github.com/squid-cache/squid/security/advisories/GHSA-hpfx-h48q-gvwg