{"id":"DEBIAN-CVE-2026-53550","details":"js-yaml is a JavaScript YAML parser and dumper. Prior to 4.2.0 and 3.15.0, a crafted YAML document can trigger algorithmic CPU exhaustion in js-yaml merge-key processing (\u003c\u003c) by repeating the same alias many times in a merge sequence. This causes quadratic parse-time behavior relative to input size and can block a Node.js worker/event loop for seconds with a relatively small payload (tens of KB), resulting in denial of service. The issue is in merge handling inside lib/loader.js. This vulnerability is fixed in 4.2.0 and 3.15.0.","modified":"2026-09-01T16:06:50.443179106Z","published":"2026-06-22T16:16:38.447Z","upstream":["CVE-2026-53550"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2026-53550"}],"affected":[{"package":{"name":"node-js-yaml","ecosystem":"Debian:12","purl":"pkg:deb/debian/node-js-yaml?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.1.0+dfsg+~4.0.5-7","4.1.1+dfsg+~4.0.9-1","4.2.0+~4.0.9-1","4.2.0+~4.0.9-2"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2026-53550.json"}},{"package":{"name":"node-js-yaml","ecosystem":"Debian:13","purl":"pkg:deb/debian/node-js-yaml?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.1.0+dfsg+~4.0.5-7","4.1.1+dfsg+~4.0.9-1","4.2.0+~4.0.9-1","4.2.0+~4.0.9-2"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2026-53550.json"}},{"package":{"name":"node-js-yaml","ecosystem":"Debian:14","purl":"pkg:deb/debian/node-js-yaml?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.2.0+~4.0.9-1"}]}],"versions":["4.1.0+dfsg+~4.0.5-7","4.1.1+dfsg+~4.0.9-1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2026-53550.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L"}]}