ALAS2023-2026-1517


Amazon Linux 2023 Security Advisory: ALAS2023-2026-1517
Advisory Released Date: 2026-04-01
Advisory Updated Date: 2026-04-01
Severity: Important

Issue Overview:

YAML::Syck versions through 1.36 for Perl has several potential security vulnerabilities including a high-severity heap buffer overflow in the YAML emitter.

The heap overflow occurs when class names exceed the initial 512-byte allocation.

The base64 decoder could read past the buffer end on trailing newlines.

strtok mutated n->type_id in place, corrupting shared node data.

A memory leak occurred in syck_hdlr_add_anchor when a node already had an anchor. The incoming anchor string 'a' was leaked on early return. (CVE-2026-4177)


Affected Packages:

perl-YAML-Syck


Issue Correction:
Run dnf update perl-YAML-Syck --releasever 2023.10.20260330 or dnf update --advisory ALAS2023-2026-1517 --releasever 2023.10.20260330 to update your system.
More information on how to update your system can be found on this page: Amazon Linux 2023 documentation

New Packages:
aarch64:
    perl-YAML-Syck-debuginfo-1.37-1.amzn2023.0.1.aarch64
    perl-YAML-Syck-debugsource-1.37-1.amzn2023.0.1.aarch64
    perl-YAML-Syck-tests-1.37-1.amzn2023.0.1.aarch64
    perl-YAML-Syck-1.37-1.amzn2023.0.1.aarch64

src:
    perl-YAML-Syck-1.37-1.amzn2023.0.1.src

x86_64:
    perl-YAML-Syck-debuginfo-1.37-1.amzn2023.0.1.x86_64
    perl-YAML-Syck-1.37-1.amzn2023.0.1.x86_64
    perl-YAML-Syck-tests-1.37-1.amzn2023.0.1.x86_64
    perl-YAML-Syck-debugsource-1.37-1.amzn2023.0.1.x86_64