CVE-2026-59870

Description

js-yaml is a JavaScript YAML parser and dumper. From 5.0.0 before 5.2.1, YAML11_SCHEMA support for the !!omap tag in src/tag/sequence/omap.ts uses omapTag.addItem() to perform a linear duplicate-key scan on every insertion, causing O(n^2) CPU consumption when yaml.load() parses a crafted ordered-map document. This issue is fixed in version 5.2.1.

CVSS Vector

References

• https://github.com/nodeca/js-yaml/commit/39f3211a2f01b3c6982710cf21434ab7060acefe
• https://github.com/nodeca/js-yaml/releases/tag/5.2.1
• https://github.com/nodeca/js-yaml/security/advisories/GHSA-724g-mxrg-4qvm
• https://github.com/nodeca/js-yaml/security/advisories/GHSA-724g-mxrg-4qvm