{"id":"CVE-2026-59870","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-59870","generatedAt":"2026-10-28T08:27:44.817Z","title":"js-yaml is a JavaScript YAML parser and dumper.","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.","published":"2026-07-08T16:16:34.000Z","lastModified":"2026-10-25T20:10:00.000Z","status":"Modified","sourceIdentifier":"security-advisories@github.com","cvss":{"version":"3.1","score":7.5,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},"cwe":["CWE-407","CWE-770"],"affected":["nodeca/js-yaml"],"epss":{"score":0.0074,"percentile":0.54376,"date":"2026-10-27","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (0.74%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[],"references":[{"url":"https://github.com/nodeca/js-yaml/commit/22a8071ef032117bc6249c330b240ac3aa2d3ded","source":"security-advisories@github.com"},{"url":"https://github.com/nodeca/js-yaml/commit/39f3211a2f01b3c6982710cf21434ab7060acefe","tags":["Patch"],"source":"security-advisories@github.com"},{"url":"https://github.com/nodeca/js-yaml/commit/c3cc4b0bb9ddb9af2dd9b61e0d56f5ce7983cd4a","source":"security-advisories@github.com"},{"url":"https://github.com/nodeca/js-yaml/releases/tag/3.15.1","source":"security-advisories@github.com"},{"url":"https://github.com/nodeca/js-yaml/releases/tag/4.3.1","source":"security-advisories@github.com"},{"url":"https://github.com/nodeca/js-yaml/releases/tag/5.2.1","tags":["Release Notes"],"source":"security-advisories@github.com"},{"url":"https://github.com/nodeca/js-yaml/security/advisories/GHSA-724g-mxrg-4qvm","tags":["Exploit","Vendor Advisory"],"source":"security-advisories@github.com"},{"url":"https://github.com/nodeca/js-yaml/security/advisories/GHSA-724g-mxrg-4qvm","tags":["Exploit","Vendor Advisory"],"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-59870","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}