CVE-2026-4177

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

Vendor Toddr
Product YAML::Syck
Weakness CWE-122
Published March 16, 2026
Last update June 30, 2026

CVSS base score

What the vulnerability does

01Description

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.

Key dates

02Disclosure timeline

March 16, 2026 CVE published
June 30, 2026 Record updated