Uncontrolled Recursion in yaml - CVE-2026-33532
Published: April 28, 2026
Vulnerability identifier: #VU128317
CSH Severity: Low
CVSS v4.0: 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
CVE-ID: CVE-2026-33532
CWE-ID: CWE-674
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: eemeli
Affected software:
yaml
yaml
Detailed vulnerability description
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.
How to mitigate CVE-2026-33532
Install security update from vendor's website.