PT-2026-60594 · Toddr · Yaml::Syck
CVE-2026-57076
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Published
2026-07-16
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Updated
2026-07-16
None
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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.
Use After Free
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Weakness Enumeration
Related Identifiers
Affected Products
Yaml::Syck