CVE catalog

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

[CVE catalog]

Severity
Critical · CVSS 9.1
Published
Source
[NVD] · [CVE record]
EPSS
0.45% · Oct 25, 2026

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.

Vulnerable and fixed packages

Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.

DistributionPackageReleaseVersionStatus
Debianlibyaml-syck-perlsid1.47-1fixed
Debianlibyaml-syck-perlforky1.47-1fixed
Debianlibyaml-syck-perltrixie1.34-2+deb13u3fixed
Debianlibyaml-syck-perltrixie-security1.34-2+deb13u3fixed
Debianlibyaml-syck-perlbookworm1.34-2+deb12u2fixed
Debianlibyaml-syck-perlbookworm-security1.34-2+deb12u3fixed
Cpelibyaml-syck-perlNot reportedNot reportedvulnerable
Alpineperl-yaml-syck3.241.45-r0fixed
Opensuseperl-YAML-Sycktumbleweed1.440.0-1.1fixed

Fixed-version evidence

DistributionPackageTypeReleaseFixed versionUrgencyOriginBugs
Debianlibyaml-syck-perlsourcesid1.36-2not yet assignedNot reportedNot reported
Debianlibyaml-syck-perlsourceforky1.36-2not yet assignedNot reportedNot reported
Debianlibyaml-syck-perlsourcetrixie1.34-2+deb13u2not yet assignedNot reportedNot reported
Debianlibyaml-syck-perlsourcebookworm1.34-2+deb12u2not yet assignedNot reportedNot reported
Alpineperl-yaml-syckapk3.241.45-r0Not reportedALPINE-CVE-2026-4177Not reported
Opensuseperl-YAML-Syckrpmtumbleweed1.440.0-1.1Not reportedOPENSUSE-SU-2026:10551-1Not reported

OpenFactory catalog packages

[Debian 12 (Bookworm)]

  • [libyaml-syck-perl]Fixed
    Details (4)

    • 1.34-2+deb12u2 · amd64 · bookworm

      Fixed · Fixed: 1.34-2+deb12u2

      nvd · libyaml-syck-perl · debian · bookworm; nvd · libyaml-syck-perl · debian · 12

    • 1.34-2+deb12u2 · arm64 · bookworm

      Fixed · Fixed: 1.34-2+deb12u2

      nvd · libyaml-syck-perl · debian · bookworm; nvd · libyaml-syck-perl · debian · 12

    • 1.34-2+deb12u3 · amd64 · bookworm-security

      Fixed · Fixed: 1.34-2+deb12u2

      nvd · libyaml-syck-perl · debian · bookworm; nvd · libyaml-syck-perl · debian · 12

    • 1.34-2+deb12u3 · arm64 · bookworm-security

      Fixed · Fixed: 1.34-2+deb12u2

      nvd · libyaml-syck-perl · debian · bookworm; nvd · libyaml-syck-perl · debian · 12

[Debian 13 (Trixie)]

  • [libyaml-syck-perl]Fixed
    Details (5)

    • 1.34-2+deb13u2 · amd64 · trixie

      Fixed · Fixed: 1.34-2+deb13u2

      nvd · libyaml-syck-perl · debian · 13

    • 1.34-2+deb13u2 · arm64 · trixie

      Fixed · Fixed: 1.34-2+deb13u2

      nvd · libyaml-syck-perl · debian · 13

    • 1.34-2+deb13u2 · amd64 · trixie-security · Historical version

      Fixed · Fixed: 1.34-2+deb13u2

      nvd · libyaml-syck-perl · debian · 13

    • 1.34-2+deb13u3 · amd64 · trixie-security

      Fixed · Fixed: 1.34-2+deb13u2

      nvd · libyaml-syck-perl · debian · 13

    • 1.34-2+deb13u3 · arm64 · trixie-security

      Fixed · Fixed: 1.34-2+deb13u2

      nvd · libyaml-syck-perl · debian · 13

[openSUSE Tumbleweed]

  • [perl-YAML-Syck]Fixed

    Source package: [perl-YAML-Syck]

    Details (1)

    • 1.470.0-1.3 · x86_64 · tumbleweed

      Fixed · Fixed: 1.440.0-1.1

      nvd · perl-YAML-Syck · opensuse · tumbleweed

Observed:

References

[CERT-Bund public advisories] · [Debian Security Tracker] · [FIRST EPSS] · [National Vulnerability Database (NVD)] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX] · [SUSE security advisories and VEX]