Linux Distros Unpatched Vulnerability : CVE-2026-56392

low Nessus Plugin ID 329674

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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.

- GNU coreutils unexpand is vulnerable to a heap-based buffer overflow due to an integer overflow during buffer allocation when processing large tab stop (-t) values. The multiplication used to calculate the allocation size can wrap around, resulting in an undersized buffer. When processing crafted input, subsequent writes exceed the allocated memory, leading to an outofbounds heap write. When running GNU coreutils unexpand with attacker-provided large tab stop (-t) arguments, this behavior leads to a crash and potentially achieve a heap write primitive depending on memory layout. This issue has been fixed in the commit b60a159fdc5bfcf9988d3a4cb6f53abe8ad5d35d (CVE-2026-56392)

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: Low

ID: 329674

File Name: unpatched_CVE_2026_56392.nasl

Version: 1.3

Type: Local

Agent: unix

Family: Misc.

Published: 7/25/2026

Updated: 7/29/2026

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: Low

Score: 2.1

Percentile: 7.91

CVSS v2

Risk Factor: Medium

Base Score: 5.8

Temporal Score: 4.9

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

CVSS Score Source: CVE-2026-56392

CVSS v3

Risk Factor: Medium

Base Score: 5.5

Temporal Score: 5.1

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

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

CVSS v4

Risk Factor: Low

Base Score: 1.8

Threat Score: 0.2

Threat Vector: CVSS:4.0/E:U

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

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:canonical:ubuntu_linux:22.04:-:lts, cpe:/o:canonical:ubuntu_linux:24.04:-:lts, cpe:/o:canonical:ubuntu_linux:26.04:-:lts, cpe:/o:debian:debian_linux:11.0, cpe:/o:debian:debian_linux:12.0, cpe:/o:debian:debian_linux:13.0, cpe:/o:debian:debian_linux:14.0, cpe:/o:redhat:enterprise_linux:10, cpe:/o:redhat:enterprise_linux:9, p-cpe:/a:canonical:ubuntu_linux:coreutils, p-cpe:/a:debian:debian_linux:coreutils, p-cpe:/a:redhat:enterprise_linux:coreutils-common, p-cpe:/a:redhat:enterprise_linux:coreutils-single, p-cpe:/a:redhat:enterprise_linux:coreutils

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: 7/24/2026

Reference Information

CVE: CVE-2026-56392

Detections

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