CVE-2026-4177 Affecting libyaml-syck-perl package, versions <1.34-2+deb13u2


Severity

Recommended
low

Based on default assessment until relevant scores are available.

Threat Intelligence

EPSS
0.43% (35th percentile)

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  • Snyk IDSNYK-DEBIAN13-LIBYAMLSYCKPERL-15689502
  • published19 Mar 2026
  • disclosed16 Mar 2026

Introduced: 16 Mar 2026

CVE-2026-4177  (opens in a new tab)

How to fix?

Upgrade Debian:13 libyaml-syck-perl to version 1.34-2+deb13u2 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream libyaml-syck-perl package and not the libyaml-syck-perl package as distributed by Debian. See How to fix? for Debian:13 relevant fixed versions and status.

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.

CVSS Base Scores

version 3.1