SB2026042856 - Uncontrolled Recursion in yaml

Description

This security bulletin contains information about 1 vulnerability.

1) Uncontrolled Recursion (CVE-ID: CVE-2026-33532)

CWE-ID: CWE-674 - Uncontrolled Recursion

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/U:Clear

The vulnerability allows a remote user to cause a denial of service.

The vulnerability exists due to uncontrolled recursion in the node resolution/composition phase when parsing deeply nested YAML collections. A remote user can supply a specially crafted YAML document to cause a denial of service.

All three public parsing APIs are affected: YAML.parse(), YAML.parseDocument(), and YAML.parseAllDocuments(). The parser CST phase is not affected.

Remediation

Install update from vendor's website.

References

• https://github.com/eemeli/yaml/security/advisories/GHSA-48c2-rrv3-qjmp
• https://github.com/advisories/GHSA-48c2-rrv3-qjmp