Buffer overflow in Toddr Yaml\

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…

Vulnerability class: Buffer Overflow

EPSS: 0.004 (34.8th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.1 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-4177?
CVE-2026-4177 is a critical-severity vulnerability in Toddr Yaml\, classified under Heap-based Buffer Overflow. CVSS score: 9.1/10. Published 2026-03-16.
How severe is CVE-2026-4177?
Critical severity. CVSS v3 base score is 9.1 out of 10.