Vulnerability Details 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 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.
Exploit prediction scoring system (EPSS) score
EPSS Score 0.0
EPSS Ranking 4.9%
CVSS Severity
CVSS v3 Score 9.1
References