CVE-2026-57076 Affecting libyaml-syck-perl package, versions <1.34-2+deb13u3


Severity

Recommended
low

Based on default assessment until relevant scores are available.

Threat Intelligence

EPSS
0.13% (3rd percentile)

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  • Snyk IDSNYK-DEBIAN13-LIBYAMLSYCKPERL-18003148
  • published17 Jul 2026
  • disclosed16 Jul 2026

Introduced: 16 Jul 2026

NewCVE-2026-57076  (opens in a new tab)

How to fix?

Upgrade Debian:13 libyaml-syck-perl to version 1.34-2+deb13u3 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 before 1.47 for Perl allow a heap use-after-free via an anchor name reused as an anchors-table key in syck_hdlr_add_anchor.

In the bundled libsyck an anchor name allocated by syck_strndup is stored both as node->anchor, freed when the node is freed, and as the key in the parser's anchors table. Freeing the node frees the shared key, and a later anchor redefinition makes st_delete compare against the freed key, so st_strcmp reads freed heap memory. Anchors are a standard YAML feature and need no special flags, so this is reached on the default Load path.

Any caller that runs Load or LoadFile on an untrusted document that redefines an anchor reaches the read of freed memory.

CVSS Base Scores

version 3.1