Linux Distros Unpatched Vulnerability : CVE-2026-4631

critical Nessus Plugin ID 305219

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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.

- Cockpit's remote login feature passes user-supplied hostnames and usernames from the web interface to the SSH client without validation or sanitization. An attacker with network access to the Cockpit web service can craft a single HTTP request to the login endpoint that injects malicious SSH options or shell commands, achieving code execution on the Cockpit host without valid credentials. The injection occurs during the authentication flow before any credential verification takes place, meaning no login is required to exploit the vulnerability. (CVE-2026-4631)

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

Solution

There is no known solution at this time.

Plugin Details

Severity: Critical

ID: 305219

File Name: unpatched_CVE_2026_4631.nasl

Version: 1.13

Type: Local

Agent: unix

Family: Misc.

Published: 4/7/2026

Updated: 5/29/2026

Supported Sensors: Frictionless Assessment AWS, Frictionless Assessment Azure, Frictionless Assessment Agent, Nessus Agent, Agentless Assessment, Nessus

Risk Information

VPR

Risk Factor: High

Score: 7.4

CVSS v2

Risk Factor: High

Base Score: 9.7

Temporal Score: 8.7

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

CVSS Score Source: CVE-2026-4631

CVSS v3

Risk Factor: Critical

Base Score: 9.8

Temporal Score: 9.3

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

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

Vulnerability Information

CPE: cpe:/o:canonical:ubuntu_linux:20.04:-:lts, cpe:/o:canonical:ubuntu_linux:25.10, cpe:/o:canonical:ubuntu_linux:24.04:-:lts, cpe:/o:canonical:ubuntu_linux:18.04:-:lts, cpe:/o:canonical:ubuntu_linux:22.04:-:lts, p-cpe:/a:canonical:ubuntu_linux:cockpit, cpe:/o:canonical:ubuntu_linux:26.04:-:lts

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

Exploit Ease: No known exploits are available

Vulnerability Publication Date: 4/7/2026

Reference Information

CVE: CVE-2026-4631

Detections

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