Linux Distros Unpatched Vulnerability : CVE-2026-6791

critical Nessus Plugin ID 334155

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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.

- When expanding paths that begin with a tilde (~) followed by a username, the internal parse_tilde function extracts the username to determine the user's home directory. The implementation allocates memory for this username directly on the stack using the strndupa macro. Because the size of this allocation was determined by the length of the user-supplied input without any bounds checks, passing an excessively long username e.g. thousands of characters, forces the thread to exhaust its stack space. Thus if an application passes untrusted, attacker-controlled input to the wordexp function, an attacker can trigger a stack clash. (CVE-2026-6791)

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: 334155

File Name: unpatched_CVE_2026_6791.nasl

Version: 1.10

Type: Local

Agent: unix

Family: Misc.

Published: 8/10/2026

Updated: 10/9/2026

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

Risk Information

VPR

Risk Factor: Low

Score: 3

Percentile: 23.68

CVSS v2

Risk Factor: Medium

Base Score: 5

Temporal Score: 4.3

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

CVSS Score Source: CVE-2026-6791

CVSS v3

Risk Factor: Medium

Base Score: 5.9

Temporal Score: 5.4

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

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

CVSS v4

Risk Factor: Critical

Base Score: 9

Threat Score: 6.6

Threat Vector: CVSS:4.0/E:U

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

Vulnerability Information

CPE: cpe:/o:canonical:ubuntu_linux:14.04:-:lts, 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:centos:centos:7, cpe:/o:debian:debian_linux:12.0, cpe:/o:debian:debian_linux:13.0, cpe:/o:redhat:enterprise_linux:7, p-cpe:/a:canonical:ubuntu_linux:eglibc, p-cpe:/a:canonical:ubuntu_linux:glibc, p-cpe:/a:centos:centos:compat-glibc-headers, p-cpe:/a:centos:centos:compat-glibc, p-cpe:/a:centos:centos:glibc-common, p-cpe:/a:centos:centos:glibc-devel, p-cpe:/a:centos:centos:glibc-headers, p-cpe:/a:centos:centos:glibc-static, p-cpe:/a:centos:centos:glibc-utils, p-cpe:/a:centos:centos:glibc, p-cpe:/a:centos:centos:nscd, p-cpe:/a:debian:debian_linux:glibc, p-cpe:/a:redhat:enterprise_linux:compat-glibc-headers, p-cpe:/a:redhat:enterprise_linux:compat-glibc, p-cpe:/a:redhat:enterprise_linux:glibc-common, p-cpe:/a:redhat:enterprise_linux:glibc-devel, p-cpe:/a:redhat:enterprise_linux:glibc-headers, p-cpe:/a:redhat:enterprise_linux:glibc-static, p-cpe:/a:redhat:enterprise_linux:glibc-utils, p-cpe:/a:redhat:enterprise_linux:glibc, p-cpe:/a:redhat:enterprise_linux:nscd

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

Exploit Ease: No known exploits are available

Reference Information

CVE: CVE-2026-6791

Detections

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