CPANSA-YAML-Syck-2026-4177: YAML-Syck vulnerability

Publisher giterlizzi Document category csaf_security_advisory
Initial release date 2026-03-16T00:00:00 Engine CSAF Perl Toolkit 0.26
Current release date 2026-03-16T00:00:00 Build Date
Current version 1 Status final
CVSS v3.1 Base Score 9.1 Severity
Original language Language en
Also referred to

Vulnerability 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.

Vulnerabilities

CVE-2026-4177

Vulnerability 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.

Weakness CWE-122 : Heap-based Buffer Overflow

Product status

Known affected
Product Score
YAML-Syck greater than 0
CVSS Version CVSS Vector CVSS Base Score CVSS Base Severity
3.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H 9.1 Critical

giterlizzi

Namespace: https://github.com/giterlizzi/

gdt@cpan.org

References

Revision history

Version Date of the revision Summary of the revision
1 Mon Mar 16 00:00:00 2026 First release

Sharing rules

TLP:WHITE
For the TLP version see: https://www.first.org/tlp/