Linux Distros Unpatched Vulnerability : CVE-2026-5089

high Nessus Plugin ID 315674

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.

- YAML::Syck versions before 1.38 for Perl has an out-of-bounds read. The base60 (sexagesimal) parsing code in perl_syck.h has a buffer underflow bug in both int#base60 and float#base60 handlers. When processing the leftmost segment of a colon-separated value (e.g., the 1 in 1:30:45), the inner while loop can decrement a pointer past the start of the string buffer: while ( colon >= ptr && *colon != ':' ) { colon--; } if ( *colon == ':' ) *colon = '\0'; // colon may be ptr-1 here When no colon is found (final/leftmost segment), colon becomes ptr-1, and the subsequent *colon dereference reads one byte before the allocated buffer. (CVE-2026-5089)

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://access.redhat.com/security/cve/cve-2026-5089

https://security-tracker.debian.org/tracker/CVE-2026-5089

https://ubuntu.com/security/CVE-2026-5089

Plugin Details

Severity: High

ID: 315674

File Name: unpatched_CVE_2026_5089.nasl

Version: 1.5

Type: Local

Agent: unix

Family: Misc.

Published: 5/20/2026

Updated: 7/6/2026

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: 2.8

Percentile: 22.6

CVSS v2

Risk Factor: Medium

Base Score: 6.4

Temporal Score: 5.4

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

CVSS Score Source: CVE-2026-5089

CVSS v3

Risk Factor: High

Base Score: 7.3

Temporal Score: 6.7

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

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

Vulnerability Information

CPE: cpe:/o:debian:debian_linux:11.0, cpe:/o:canonical:ubuntu_linux:20.04:-:lts, cpe:/o:canonical:ubuntu_linux:25.10, p-cpe:/a:canonical:ubuntu_linux:libyaml-syck-perl, cpe:/o:canonical:ubuntu_linux:24.04:-:lts, cpe:/o:canonical:ubuntu_linux:16.04:-:lts, p-cpe:/a:debian:debian_linux:libyaml-syck-perl, cpe:/o:canonical:ubuntu_linux:18.04:-:lts, cpe:/o:redhat:enterprise_linux:6, p-cpe:/a:centos:centos:perl-yaml-syck, cpe:/o:centos:centos:8, cpe:/o:debian:debian_linux:13.0, p-cpe:/a:redhat:enterprise_linux:perl-yaml-syck, cpe:/o:canonical:ubuntu_linux:22.04:-:lts, cpe:/o:debian:debian_linux:12.0, cpe:/o:redhat:enterprise_linux:8, 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: 5/12/2026

Reference Information

CVE: CVE-2026-5089