Linux Distros Unpatched Vulnerability : CVE-2026-12505

high Nessus Plugin ID 321661

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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.

- A flaw was found in the cifs-utils package where the cifs.upcall helper fails to securely drop its root privileges before looking up user information inside a user-controlled environment. A local, low privileged attacker can exploit this by using a crafted request_key payload to trick the root-owned helper into entering a custom environment (namespace) containing a malicious NSS module. This forces the system to load the attacker's controlled NSS Module and configuration, allowing them to execute arbitrary commands as the root user, elevating their privileges and fully compromising the system. (CVE-2026-12505)

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: High

ID: 321661

File Name: unpatched_CVE_2026_12505.nasl

Version: 1.5

Type: Local

Agent: unix

Family: Misc.

Published: 6/20/2026

Updated: 7/6/2026

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

Risk Information

VPR

Risk Factor: Medium

Score: 4.9

Percentile: 58.04

CVSS v2

Risk Factor: Medium

Base Score: 6.6

Temporal Score: 5.6

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

CVSS Score Source: CVE-2026-12505

CVSS v3

Risk Factor: High

Base Score: 7.8

Temporal Score: 7.1

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

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

Vulnerability Information

CPE: cpe:/o:debian:debian_linux:11.0, cpe:/o:centos:centos:7, cpe:/o:redhat:enterprise_linux:7, cpe:/o:redhat:enterprise_linux:8, cpe:/o:canonical:ubuntu_linux:18.04:-:lts, cpe:/o:canonical:ubuntu_linux:16.04:-:lts, cpe:/o:canonical:ubuntu_linux:20.04:-:lts, p-cpe:/a:centos:centos:cifs-utils, p-cpe:/a:redhat:enterprise_linux:cifs-utils, cpe:/o:centos:centos:8, cpe:/o:canonical:ubuntu_linux:14.04:-:lts, cpe:/o:canonical:ubuntu_linux:22.04:-:lts, p-cpe:/a:debian:debian_linux:cifs-utils, p-cpe:/a:canonical:ubuntu_linux:cifs-utils, cpe:/o:redhat:enterprise_linux:9, cpe:/o:debian:debian_linux:12.0, cpe:/o:canonical:ubuntu_linux:24.04:-:lts, cpe:/o:debian:debian_linux:13.0, p-cpe:/a:redhat:enterprise_linux:cifs-utils-devel, p-cpe:/a:redhat:enterprise_linux:pam_cifscreds, cpe:/o:debian:debian_linux:14.0, p-cpe:/a:centos:centos:cifs-utils-devel, p-cpe:/a:centos:centos:pam_cifscreds, cpe:/o:canonical:ubuntu_linux:25.10, cpe:/o:canonical:ubuntu_linux:26.04:-:lts

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: 6/18/2026

Reference Information

CVE: CVE-2026-12505

Detections

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