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

Overview

Severity

Critical (CVSS 9.1)

CVSS Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H

Exploit Status

Not Exploited

Patch Tuesday

2026-Mar

Released

2026-10-21

EPSS Score

0.63% (percentile: 49.2%)

Affected Products (1)

Other

• 0-17084

Revision History

• 2026-10-21: Information published.