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.

rocky_linux RLSA-2026:8317: RLSA-2026:8317: squid:4 security update (Important)

redhat RHSA-2026:8317: RHSA-2026:8317: squid:4 security update (Important)

The remote RockyLinux 10 host has packages installed that are affected by multiple vulnerabilities as referenced in the RLSA-2026:8119 advisory.

    * squid: Squid: Denial of Service via heap Use-After-Free vulnerability in ICP handling (CVE-2026-33526)

    * Squid: Squid: Denial of Service via crafted ICP traffic (CVE-2026-32748)

Tenable has extracted the preceding description block directly from the RockyLinux security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote AlmaLinux 10 host has a package installed that is affected by multiple vulnerabilities as referenced in the ALSA-2026:8119 advisory.

    * squid: Squid: Denial of Service via heap Use-After-Free vulnerability in ICP handling (CVE-2026-33526)
      * Squid: Squid: Denial of Service via crafted ICP traffic (CVE-2026-32748)

Tenable has extracted the preceding description block directly from the AlmaLinux security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote Oracle Linux 10 host has a package installed that is affected by multiple vulnerabilities as referenced in the ELSA-2026-8119 advisory.

    - Resolves: RHEL-160667 - squid: Squid: Denial of Service via       crafted ICP traffic (CVE-2026-32748)

Tenable has extracted the preceding description block directly from the Oracle Linux security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote Redhat Enterprise Linux 10 host has a package installed that is affected by multiple vulnerabilities as referenced in the RHSA-2026:8119 advisory.

    Squid is a high-performance proxy caching server for web clients, supporting FTP, and HTTP data objects.

    Security Fix(es):

    * squid: Squid: Denial of Service via heap Use-After-Free vulnerability in ICP handling (CVE-2026-33526)

    * Squid: Squid: Denial of Service via crafted ICP traffic (CVE-2026-32748)

    For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and     other related information, refer to the CVE page(s) listed in the References section.

Tenable has extracted the preceding description block directly from the Red Hat Enterprise Linux security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The version of squid installed on the remote host is prior to 3.5.20-17. It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2-2026-3242 advisory.

    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/2026/03/25/3NOTE: 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/2026/03/25/2NOTE: Fixed by: https://github.com/squid-     cache/squid/commit/8a7d42f9d44befb8fcbbb619505587c8de6a1e91 (SQUID_7_5) (CVE-2026-33526)

Tenable has extracted the preceding description block directly from the tested product security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2023-2026-1569 advisory.

    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/2026/03/25/3NOTE: 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/2026/03/25/2NOTE: Fixed by: https://github.com/squid-     cache/squid/commit/8a7d42f9d44befb8fcbbb619505587c8de6a1e91 (SQUID_7_5) (CVE-2026-33526)

Tenable has extracted the preceding description block directly from the tested product security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote Ubuntu 22.04 LTS / 24.04 LTS / 25.10 host has packages installed that are affected by multiple vulnerabilities as referenced in the USN-8157-1 advisory.

    It was discovered that Squid incorrectly handled certain ICP traffic. In environments where ICP support is     enabled, a remote attacker could use this issue to cause Squid to crash, resulting in a denial of service,     or obtain small amounts of sensitive information.

Tenable has extracted the preceding description block directly from the Ubuntu security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote RockyLinux 9 host has packages installed that are affected by multiple vulnerabilities as referenced in the RLSA-2026:6301 advisory.

    * squid: Squid: Denial of Service via heap Use-After-Free vulnerability in ICP handling (CVE-2026-33526)

    * Squid: Squid: Denial of Service via crafted ICP traffic (CVE-2026-32748)

Tenable has extracted the preceding description block directly from the RockyLinux security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote Redhat Enterprise Linux 9 host has a package installed that is affected by multiple vulnerabilities as referenced in the RHSA-2026:6301 advisory.

    Squid is a high-performance proxy caching server for web clients, supporting FTP, and HTTP data objects.

    Security Fix(es):

    * squid: Squid: Denial of Service via heap Use-After-Free vulnerability in ICP handling (CVE-2026-33526)

    * Squid: Squid: Denial of Service via crafted ICP traffic (CVE-2026-32748)

    For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and     other related information, refer to the CVE page(s) listed in the References section.

Tenable has extracted the preceding description block directly from the Red Hat Enterprise Linux security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote MiracleLinux 9 host has a package installed that is affected by multiple vulnerabilities as referenced in the AXSA:2026-387:02 advisory.

    * squid: Squid: Denial of Service via heap Use-After-Free vulnerability in ICP handling (CVE-2026-33526)
      * Squid: Squid: Denial of Service via crafted ICP traffic (CVE-2026-32748)

Tenable has extracted the preceding description block directly from the MiracleLinux security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote AlmaLinux 9 host has a package installed that is affected by multiple vulnerabilities as referenced in the ALSA-2026:6301 advisory.

    * squid: Squid: Denial of Service via heap Use-After-Free vulnerability in ICP handling (CVE-2026-33526)
      * Squid: Squid: Denial of Service via crafted ICP traffic (CVE-2026-32748)

Tenable has extracted the preceding description block directly from the AlmaLinux security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote Oracle Linux 9 host has a package installed that is affected by multiple vulnerabilities as referenced in the ELSA-2026-6301 advisory.

    - Resolves: RHEL-160692 - squid: Squid: Denial of Service via       crafted ICP traffic (CVE-2026-32748)

Tenable has extracted the preceding description block directly from the Oracle Linux security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The version of Squid on the remote host is prior to 7.5. It is, therefore, affected by multiple vulnerabilities:

  - Due to heap Use-After-Free, Squid is vulnerable to Denial of Service when handling ICP traffic. This attack is     limited to Squid deployments that explicitly enable ICP support. (CVE-2026-33526)

  - Due to improper input validation, Squid is vulnerable to out of bounds read when handling ICP traffic. This     allows a remote attacker to receive small amounts of memory potentially containing sensitive information.
    (CVE-2026-33515)

  - 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. (CVE-2026-32748)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - 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. (CVE-2026-33526)

Note that Nessus relies on the presence of the package as reported by the vendor.

ID	Name	Product	Family	Severity
306532	RockyLinux 10 : squid (RLSA-2026:8119)	Nessus	Rocky Linux Local Security Checks	critical
306525	AlmaLinux 10 : squid (ALSA-2026:8119)	Nessus	Alma Linux Local Security Checks	critical
306468	Oracle Linux 10 : squid (ELSA-2026-8119)	Nessus	Oracle Linux Local Security Checks	critical
306404	RHEL 10 : squid (RHSA-2026:8119)	Nessus	Red Hat Local Security Checks	critical
306300	Amazon Linux 2 : squid, --advisory ALAS2-2026-3242 (ALAS-2026-3242)	Nessus	Amazon Linux Local Security Checks	critical
306231	Amazon Linux 2023 : squid (ALAS2023-2026-1569)	Nessus	Amazon Linux Local Security Checks	critical
306089	Ubuntu 22.04 LTS / 24.04 LTS / 25.10 : Squid vulnerabilities (USN-8157-1)	Nessus	Ubuntu Local Security Checks	critical
305128	RockyLinux 9 : squid (RLSA-2026:6301)	Nessus	Rocky Linux Local Security Checks	critical
304995	RHEL 9 : squid (RHSA-2026:6301)	Nessus	Red Hat Local Security Checks	critical
304710	MiracleLinux 9 : squid-5.5-22.el9_7.4 (AXSA:2026-387:02)	Nessus	Miracle Linux Local Security Checks	critical
304540	AlmaLinux 9 : squid (ALSA-2026:6301)	Nessus	Alma Linux Local Security Checks	critical
304491	Oracle Linux 9 : squid (ELSA-2026-6301)	Nessus	Oracle Linux Local Security Checks	critical
303933	Squid < 7.5 Multiple Vulnerabilities	Nessus	Firewalls	critical
303680	Linux Distros Unpatched Vulnerability : CVE-2026-33526	Nessus	Misc.	critical

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