CVE-2025-11683 Affecting libyaml-syck-perl package, versions <1.31-1ubuntu0.1~esm1


Severity

Recommended
medium

Based on Ubuntu security rating.

Threat Intelligence

EPSS
0.03% (7th percentile)

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  • Snyk IDSNYK-UBUNTU2004-LIBYAMLSYCKPERL-13641272
  • published21 Mar 2026
  • disclosed16 Oct 2025

Introduced: 16 Oct 2025

CVE-2025-11683  (opens in a new tab)

How to fix?

Upgrade Ubuntu:20.04 libyaml-syck-perl to version 1.31-1ubuntu0.1~esm1 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 Ubuntu. See How to fix? for Ubuntu:20.04 relevant fixed versions and status.

YAML::Syck versions before 1.36 for Perl has missing null-terminators which causes out-of-bounds read and potential information disclosure

Missing null terminators in token.c leads to but-of-bounds read which allows adjacent variable to be read

The issue is seen with complex YAML files with a hash of all keys and empty values.  There is no indication that the issue leads to accessing memory outside that allocated to the module.

CVSS Base Scores

version 3.1