Detections
Analytics

Ubuntu 16.04 LTS / 18.04 LTS / 20.04 LTS / 22.04 LTS / 24.04 LTS : Squid vulnerabilities (USN-8941-1)

critical Nessus Plugin ID 369509

Language:

Synopsis

The remote Ubuntu host is missing one or more security updates.

Description

The remote Ubuntu 16.04 LTS / 18.04 LTS / 20.04 LTS / 22.04 LTS / 24.04 LTS host has packages installed that are affected by multiple vulnerabilities as referenced in the USN-8941-1 advisory.

 It was discovered that Squid incorrectly handled certain HTTP Transfer- Encoding headers. An attacker could possibly use this issue to perform HTTP request smuggling attacks, bypass security mechanisms, or poison web caches.

 (CVE-2026-61642)

 It was discovered that Squid incorrectly handled certain cache digest replies, which could lead to a buffer overflow. A remote attacker could possibly use this issue to cause Squid to crash, resulting in a denial of service. This issue only affected Ubuntu 16.04 LTS, Ubuntu 18.04 LTS, and Ubuntu 20.04 LTS.
 (CVE-2026-50012)

 It was discovered that Squid incorrectly handled parsing certain FTP directory listings. A remote attacker could possibly use this issue to obtain sensitive information. This issue only affected Ubuntu 16.04 LTS, Ubuntu 18.04 LTS, and Ubuntu 20.04 LTS. (CVE-2026-47729)

 It was discovered that Squid incorrectly handled certain ICP traffic. A remote attacker could possibly use this issue to cause Squid to crash, resulting in a denial of service. This issue only affected Ubuntu 16.04 LTS, Ubuntu 18.04 LTS, and Ubuntu 20.04 LTS. (CVE-2026-32748, CVE-2026-33526)

 It was discovered that Squid incorrectly handled certain ICP requests. A remote attacker could possibly use this issue to obtain sensitive information. This issue only affected Ubuntu 16.04 LTS, Ubuntu 18.04 LTS, and Ubuntu 20.04 LTS. (CVE-2026-33515)

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.

Solution

Update the affected packages.

See Also

https://ubuntu.com/security/notices/USN-8941-1

Plugin Details

Severity: Critical

ID: 369509

File Name: ubuntu_USN-8941-1.nasl

Version: 1.2

Type: Local

Agent: unix

Published: 10/21/2026

Updated: 10/22/2026

Supported Sensors: Frictionless Assessment AWS, Frictionless Assessment Azure, Frictionless Assessment Agent, Nessus Agent, Agentless Assessment, Continuous Assessment, Tenable Cloud Security, Tenable Self-Hosted Container Security, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 6

Percentile: 96.21

CVSS v2

Risk Factor: Medium

Base Score: 6.8

Temporal Score: 5.3

Vector: CVSS2#AV:N/AC:L/Au:M/C:N/I:P/A:C

CVSS Score Source: CVE-2026-50012

CVSS v3

Risk Factor: Medium

Base Score: 6.5

Temporal Score: 5.9

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

Temporal Vector: CVSS:3.0/E:P/RL:O/RC:C

CVSS Score Source: CVE-2026-33515

CVSS v4

Risk Factor: Critical

Base Score: 9.2

Threat Score: 8.7

Threat Vector: CVSS:4.0/E:P

Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H

CVSS Score Source: CVE-2026-33526

Vulnerability Information

CPE: cpe:/o:canonical:ubuntu_linux:16.04:-:lts, cpe:/o:canonical:ubuntu_linux:18.04:-:lts, cpe:/o:canonical:ubuntu_linux:20.04:-:lts, cpe:/o:canonical:ubuntu_linux:22.04:-:lts, cpe:/o:canonical:ubuntu_linux:24.04:-:lts, p-cpe:/a:canonical:ubuntu_linux:squid-cgi, p-cpe:/a:canonical:ubuntu_linux:squid-common, p-cpe:/a:canonical:ubuntu_linux:squid-openssl, p-cpe:/a:canonical:ubuntu_linux:squid-purge, p-cpe:/a:canonical:ubuntu_linux:squid3, p-cpe:/a:canonical:ubuntu_linux:squid, p-cpe:/a:canonical:ubuntu_linux:squidclient

Required KB Items: Host/cpu, Host/Debian/dpkg-l, Host/Ubuntu, Host/Ubuntu/release

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 10/20/2026

Vulnerability Publication Date: 10/20/2026

Reference Information

CVE: CVE-2026-32748, CVE-2026-33515, CVE-2026-33526, CVE-2026-47729, CVE-2026-50012, CVE-2026-61642

USN: 8941-1