UBUNTU-CVE-2026-33526

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    UBUNTU-CVE-2026-33526

    Published: 26 Mar 2026Last Modified: 21 Oct 2026
    Upstream:
    CVE-2026-33526

    Summary:

    Details: 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.

    References: https://ubuntu.com/security/CVE-2026-33526, https://www.cve.org/CVERecord?id=CVE-2026-33526, https://www.openwall.com/lists/oss-security/2026/03/25/2, https://ubuntu.com/security/notices/USN-8157-1, https://ubuntu.com/security/notices/USN-8941-1

    Affected packages

    Package

    Name: squid3

    Purl: pkg:deb/ubuntu/squid3?arch=source&distro=esm-infra-legacy%2Fxenial

    Affected ranges

    Type: ECOSYSTEM

    Events:

    Introduced- 0
    Fixed -3.5.12-1ubuntu7.16+esm7

    Affected versions

    3.3.8-1ubuntu16
    3.3.8-1ubuntu17

    Common Vulnerability Scoring System

    Attack Vector
    Network
    Adjacent
    Local
    Physical
    Privileges Required
    None
    Low
    High
    User Interaction
    None
    Required
    Scope
    Unchanged
    Changed
    Confidentiality
    None
    Low
    High
    Integrity
    None
    Low
    High
    Availability
    None
    Low
    High
    UBUNTU-CVE-2026-33526 | CVE-DB