CVE-2026-4177

Description

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.

Affected packages (2)

• Debian/libyaml-syck-perlfrom 0, < 1.34-1+deb11u1
• Debian/libyaml-syck-perlfrom 0, < 1.34-2+deb12u2

CVSS scores

References (1)

• ADVISORYhttps://security-tracker.debian.org/tracker/CVE-2026-4177