Linux Distros Unpatched Vulnerability : CVE-2026-42177

medium Nessus Plugin ID 326441

Synopsis

The Linux/Unix host has one or more packages installed with a vulnerability that the vendor indicates will not be patched.

Description

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

- linux-entra-sso is a browser plugin for Linux to SSO on Microsoft Entra ID. Prior to 1.8.1, platform/chrome/js/platform-chrome.js:69-88 registers a single declarativeNetRequest rule whose urlFilter is Platform.SSO_URL + /*, i.e. https://login.microsoftonline.com/*. Chrome's urlFilter without a | or || anchor is substring-matched against the full request URL. The same applied rule action is modifyHeaders that attaches the Entra ID Primary Refresh Token cookie. The Firefox adapter in platform/firefox/js/platform-firefox.js:53 performs a belt-and-braces startsWith(Platform.SSO_URL) check before injecting the header; the Chrome adapter does not. When the extension holds broad host permissions through the optional_host_permissions: [https://*/*] declared in platform/chrome/manifest.json:34, a main-frame navigation to a URL whose path embeds https://login.microsoftonline.com/ causes Chrome to attach the PRT cookie to the request to the attacker-controlled host. This vulnerability is fixed in 1.8.1. (CVE-2026-42177)

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

Solution

There is no known solution at this time.

See Also

https://ubuntu.com/security/CVE-2026-42177

Plugin Details

Severity: Medium

ID: 326441

File Name: unpatched_CVE_2026_42177.nasl

Version: 1.1

Type: Local

Agent: unix

Family: Misc.

Published: 7/13/2026

Updated: 7/13/2026

Supported Sensors: Nessus Agent, Nessus

Risk Information

VPR

Risk Factor: Low

Score: 3

Percentile: 23.69

CVSS v2

Risk Factor: Medium

Base Score: 5.8

Temporal Score: 4.9

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

CVSS Score Source: CVE-2026-42177

CVSS v3

Risk Factor: Medium

Base Score: 5.3

Temporal Score: 4.9

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

Temporal Vector: CVSS:3.0/E:U/RL:U/RC:C

Vulnerability Information

CPE: cpe:/o:canonical:ubuntu_linux:26.04:-:lts, p-cpe:/a:canonical:ubuntu_linux:linux-entra-sso

Required KB Items: Host/cpu, Host/local_checks_enabled, global_settings/vendor_unpatched, Host/OS/identifier

Exploit Ease: No known exploits are available

Vulnerability Publication Date: 5/12/2026

Reference Information

CVE: CVE-2026-42177