Disclosure summary
js-yaml is a JavaScript YAML parser and dumper. Prior to 3.15.1, 4.3.1, and 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. In v3 and v4, !!omap is active and exploitable by default. v5 doesn't use !!omap by default, and the chances of activating it are very low.This issue is fixed in 3.15.1, 4.3.1, and 5.2.1.
Source-reported weakness categories
CWE-407, CWE-770
Source-specific records & product guidance
Sources retain their own attribution and scoring. Follow the original record to confirm affected versions, fixed releases, and configuration conditions.
NIST National Vulnerability Database · NVD-CVE-2026-59870
Open original source · Updated Oct 06, 2026
Only CPE matches marked vulnerable=true are indexed. AND/OR platform conditions must be checked in the original NVD record.
| Vendor | Product / association | Version / bounds |
|---|---|---|
| nodeca | js-yaml | * {"versionStartIncluding":"5.0.0","versionEndExcluding":"5.2.1"} |
Original records & references
- NIST NVD record
- CVE Program record
- github.com
- github.com — Patch
- github.com
- github.com
- github.com
- github.com — Release Notes
- github.com — Exploit, Vendor Advisory
- github.com — Exploit, Vendor Advisory
PUBLISHED 2026-07-08T12:16:33-04:00
MODIFIED 2026-10-06T12:17:08-04:00
INGESTED 2026-10-10T20:25:11-04:00