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Critical USN-8925-1 2 CVEs

libyaml-perl vulnerabilities

Published Oct 14, 2026 · Updated Oct 14, 2026

Ecosystem: Ubuntu

Summary

Dominique Dumont discovered that YAML-LibYAML did not correctly handle
certain reflection operations. If a user or system were tricked into
opening a specially crafted file, an attacker could possibly use this issue
to delete files. This issue only affected Ubuntu 16.04 LTS and Ubuntu 18.04
LTS. (CVE-2017-20285)

It was discovered that YAML-LibYAML did not correctly handle parsing
certain documents. If a user or automated system were tricked into opening
a specially crafted file, an attacker could possibly use this issue to
execute arbitrary code. This issue only affected Ubuntu 16.04 LTS and
Ubuntu 18.04 LTS. (CVE-2019-25777)

It was discovered that YAML-LibYAML contained a regular expression
susceptible to catastrophic backtracking. If a user or automated system
were tricked into opening a specially crafted file, an attacker could
possibly use this issue to cause a denial of service. (CVE-2026-63676)

Fixed packages 6

ReleasePackageFixed in
Ubuntu · 22.04 LTS 22.04:LTS libyaml-perl 1.30-1ubuntu0.22.04.1
Ubuntu · 24.04 LTS 24.04:LTS libyaml-perl 1.31-1ubuntu0.24.04.1
Ubuntu · Pro 16.04 LTS Pro:16.04:LTS libyaml-perl 1.15-1ubuntu0.1~esm1
Ubuntu · Pro 18.04 LTS Pro:18.04:LTS libyaml-perl 1.24-1ubuntu0.1~esm1
Ubuntu · Pro 20.04 LTS Pro:20.04:LTS libyaml-perl 1.30-1ubuntu0.20.04.1~esm1
Ubuntu · Pro 26.04 LTS Pro:26.04:LTS libyaml-perl 1.31-1ubuntu0.26.04.1~esm1

Vulnerabilities 2

  • Critical 9.1
    CVE-2017-20285

    YAML versions before 1.30 for Perl allow a loaded document to trigger the DESTROY method of arbitrary classes

    YAML versions before 1.30 for Perl allow a loaded document to trigger the DESTROY method of arbitrary classes. A perl/hash:Class tag blesses a hash into the class it names. The document supplies the object's fields, and Perl calls DESTROY when it goes out of …

    libyaml-perl libyaml-perl Debian Ubuntu
  • High 7.3
    CVE-2019-25777

    YAML versions before 1.27_001 for Perl allow a loaded perl/glob document to replace any package variable, which can lead to arbitrary code execution

    YAML versions before 1.27_001 for Perl allow a loaded perl/glob document to replace any package variable, which can lead to arbitrary code execution. A perl/glob document names a package and a symbol, and supplies the value assigned to it. Nothing restricts t…

    libyaml-perl libyaml-perl Debian Ubuntu

References

  • report
    https://ubuntu.com/security/CVE-2017-20285
  • report
    https://ubuntu.com/security/CVE-2019-25777
  • report
    https://ubuntu.com/security/CVE-2026-63676