VulnerabilityAnalyzed
CVE-2026-59870
js-yaml is a JavaScript YAML parser and dumper.
HIGH 7.5EPSS 0.64%
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.64%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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 3.1
- 7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- EPSS
- 0.64% probability · 49th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-407, CWE-770
- Affected
- nodeca/js-yaml
- Source
- security-advisories@github.com
References
- https://github.com/nodeca/js-yaml/commit/39f3211a2f01b3c6982710cf21434ab7060acefePatch
- https://github.com/nodeca/js-yaml/releases/tag/5.2.1Release Notes
- https://github.com/nodeca/js-yaml/security/advisories/GHSA-724g-mxrg-4qvmExploit, Vendor Advisory
- https://github.com/nodeca/js-yaml/security/advisories/GHSA-724g-mxrg-4qvmExploit, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.