Skip to content
OpenAdvisories
High ALAS2023-2026-1517 1 CVE

Important: perl-YAML-Syck security update (Amazon Linux 2023)

Published Mar 30, 2026 · Updated Apr 1, 2026

Summary

Package updates are available for Amazon Linux 2023 that fix the following vulnerabilities: CVE-2026-4177: 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.

Fixed packages 4

ReleasePackageFixed in
Amazon Linux · 2023 perl-YAML-Syck 0:1.37-1.amzn2023.0.1
Amazon Linux · 2023 perl-YAML-Syck-debuginfo 0:1.37-1.amzn2023.0.1
Amazon Linux · 2023 perl-YAML-Syck-debugsource 0:1.37-1.amzn2023.0.1
Amazon Linux · 2023 perl-YAML-Syck-tests 0:1.37-1.amzn2023.0.1

Vulnerabilities 1

  • Critical 9.1

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

    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 c…

References

  • web
    https://alas.aws.amazon.com/cve/html/CVE-2026-4177.html