Vulnerability Description
js-yaml is a JavaScript YAML parser and dumper. From 3.0.0 before 3.15.0 and from 4.0.0 before 4.3.0, js-yaml can spend quadratic CPU time parsing a document whose size grows only linearly when a chain of mappings uses merge keys where each mapping merges the previous one. This issue is fixed in versions 3.15.0 and 4.3.0.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Nodeca | Js-Yaml | >= 3.0.0, < 3.15.0 |
Related Weaknesses (CWE)
References
- https://github.com/nodeca/js-yaml/commit/24f13e79ee1343a7e30bd6f6c9d9cdbf0ac9b2bPatch
- https://github.com/nodeca/js-yaml/commit/59423c6f8cdc78742ac00e25a4dd39ef16b702ePatch
- https://github.com/nodeca/js-yaml/releases/tag/3.15.0Release Notes
- https://github.com/nodeca/js-yaml/releases/tag/4.3.0Release Notes
- https://github.com/nodeca/js-yaml/security/advisories/GHSA-52cp-r559-cp3mExploitVendor Advisory
- https://github.com/nodeca/js-yaml/security/advisories/GHSA-52cp-r559-cp3mExploitVendor Advisory
FAQ
What is CVE-2026-59869?
CVE-2026-59869 is a vulnerability with a CVSS score of 7.5 (HIGH). js-yaml is a JavaScript YAML parser and dumper. From 3.0.0 before 3.15.0 and from 4.0.0 before 4.3.0, js-yaml can spend quadratic CPU time parsing a document whose size grows only linearly when a chai...
How severe is CVE-2026-59869?
CVE-2026-59869 has been rated HIGH with a CVSS base score of 7.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-59869?
Check the references section above for vendor advisories and patch information. Affected products include: Nodeca Js-Yaml.