{"cve":"CVE-2026-59870","nvd":{"published":"2026-07-08T16:16:33.580","modified":"2026-10-25T20:10:00.147","status":"Modified","description":"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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","score":7.5},"cwes":["CWE-770","CWE-407"],"references":["https://github.com/nodeca/js-yaml/commit/22a8071ef032117bc6249c330b240ac3aa2d3ded","https://github.com/nodeca/js-yaml/commit/39f3211a2f01b3c6982710cf21434ab7060acefe","https://github.com/nodeca/js-yaml/commit/c3cc4b0bb9ddb9af2dd9b61e0d56f5ce7983cd4a","https://github.com/nodeca/js-yaml/releases/tag/3.15.1","https://github.com/nodeca/js-yaml/releases/tag/4.3.1"],"products":["nodeca:js-yaml"],"source":"nvd","synced_at":"2026-10-25T23:44:34.550481224+00:00"},"epss":{"cve":"CVE-2026-59870","score":0.0074,"percentile":0.54298,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-724g-mxrg-4qvm","url":"https://osv.dev/vulnerability/GHSA-724g-mxrg-4qvm","summary":"js-yaml: Quadratic-complexity (O(n^2)) DoS via !!omap tag in YAML11_SCHEMA","modified":"2026-09-10T03:50:51.442129612Z","packages":[{"ecosystem":"npm","name":"js-yaml","purl":"pkg:npm/js-yaml","ranges":[">=5.0.0 <5.2.1"],"fixed":["5.2.1"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}