Heap-based Buffer Overflow Affecting cpan-authors/YAML-Syck package, versions [,1.37-01)
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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- published23 Mar 2026
- disclosed17 Mar 2026
- creditUnknown
Introduced: 17 Mar 2026
CVE-2026-4177 (opens in a new tab)How to fix?
Upgrade cpan-authors/YAML-Syck to version 1.37-01 or higher.
Overview
Affected versions of this package are vulnerable to Heap-based Buffer Overflow via the strcat(tag, ref) with long class names. An attacker can cause a heap buffer overflow by providing class names that exceed the initial allocation size, potentially leading to memory corruption or application crash. Additional issues include the base64 decoder reading past the buffer end on trailing newlines, mutation of n->type_id in place by strtok which can corrupt shared node data, and a memory leak in syck_hdlr_add_anchor when a node already has an anchor.