Amazon Linux 2023 : perl-YAML-Syck, perl-YAML-Syck-tests (ALAS2023-2026-1769)

high Nessus Plugin ID 319805

Synopsis

The remote Amazon Linux 2023 host is missing a security update.

Description

It is, therefore, affected by a vulnerability as referenced in the ALAS2023-2026-1769 advisory.

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)

Tenable has extracted the preceding description block directly from the tested product security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

Solution

Run 'dnf update perl-YAML-Syck --releasever 2023.12.20260608' or or 'dnf update --advisory ALAS2023-2026-1769 --releasever 2023.12.20260608' to update your system.

Plugin Details

Severity: High

ID: 319805

File Name: al2023_ALAS2023-2026-1769.nasl

Version: 1.1

Type: Local

Agent: unix

Family: Amazon Linux Local Security Checks

Published: 6/8/2026

Updated: 6/8/2026

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

Risk Information

VPR

Risk Factor: Medium

Score: 4.2

CVSS v2

Risk Factor: High

Base Score: 7.5

Temporal Score: 5.5

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

CVSS Score Source: CVE-2026-5089

CVSS v3

Risk Factor: High

Base Score: 7.3

Temporal Score: 6.4

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:O/RC:C

Vulnerability Information

CPE: p-cpe:/a:amazon:linux:perl-yaml-syck-debugsource, p-cpe:/a:amazon:linux:perl-yaml-syck-tests, p-cpe:/a:amazon:linux:perl-yaml-syck, p-cpe:/a:amazon:linux:perl-yaml-syck-debuginfo, cpe:/o:amazon:linux:2023

Required KB Items: Host/local_checks_enabled, Host/AmazonLinux/release, Host/AmazonLinux/rpm-list

Exploit Ease: No known exploits are available

Patch Publication Date: 6/8/2026

Vulnerability Publication Date: 5/12/2026

Reference Information

CVE: CVE-2026-5089

Detections

Analytics