{"id":"CVE-2026-59869","state":"PUBLISHED","title":"js-yaml: YAML merge-key chains can force quadratic CPU consumption","description":"js-yaml is a JavaScript YAML parser and dumper. From 3.0.0 before 3.15.0 and from 4.0.0 before 4.3.0, js-yaml can spend quadratic CPU time parsing a document whose size grows only linearly when a chain of mappings uses merge keys where each mapping merges the previous one. This issue is fixed in versions 3.15.0 and 4.3.0.","publishedAt":"2026-07-08T15:15:54.675Z","updatedAt":"2026-07-09T15:14:29.753Z","severity":{"score":7.5,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","source":"GitHub_M"},"assigner":"GitHub_M","products":["nodeca js-yaml"],"affected":[{"vendor":"nodeca","product":"js-yaml","versions":[{"version":">= 3.0.0, < 3.15.0","status":"affected"},{"version":">= 4.0.0, < 4.3.0","status":"affected"}]}],"references":["https://github.com/nodeca/js-yaml/security/advisories/GHSA-52cp-r559-cp3m","https://github.com/nodeca/js-yaml/commit/24f13e79ee1343a7e30bd6f6c9d9cdbf0ac9b2b7","https://github.com/nodeca/js-yaml/commit/59423c6f8cdc78742ac00e25a4dd39ef16b702e4","https://github.com/nodeca/js-yaml/releases/tag/3.15.0","https://github.com/nodeca/js-yaml/releases/tag/4.3.0"],"weaknesses":["CWE-407"],"ingestedAt":"2026-10-29T20:12:32.778Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/59xxx/CVE-2026-59869.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-59869","state":"PUBLISHED","datePublished":"2026-07-08T15:15:54.675Z","dateUpdated":"2026-07-09T15:14:29.753Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-07-07T15:41:53.607Z"},"containers":{"cna":{"title":"js-yaml: YAML merge-key chains can force quadratic CPU consumption","descriptions":[{"lang":"en","value":"js-yaml is a JavaScript YAML parser and dumper. From 3.0.0 before 3.15.0 and from 4.0.0 before 4.3.0, js-yaml can spend quadratic CPU time parsing a document whose size grows only linearly when a chain of mappings uses merge keys where each mapping merges the previous one. This issue is fixed in versions 3.15.0 and 4.3.0."}],"affected":[{"vendor":"nodeca","product":"js-yaml","versions":[{"version":">= 3.0.0, < 3.15.0","status":"affected"},{"version":">= 4.0.0, < 4.3.0","status":"affected"}]}],"references":[{"url":"https://github.com/nodeca/js-yaml/security/advisories/GHSA-52cp-r559-cp3m","name":"https://github.com/nodeca/js-yaml/security/advisories/GHSA-52cp-r559-cp3m","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/nodeca/js-yaml/commit/24f13e79ee1343a7e30bd6f6c9d9cdbf0ac9b2b7","name":"https://github.com/nodeca/js-yaml/commit/24f13e79ee1343a7e30bd6f6c9d9cdbf0ac9b2b7","tags":["x_refsource_MISC"]},{"url":"https://github.com/nodeca/js-yaml/commit/59423c6f8cdc78742ac00e25a4dd39ef16b702e4","name":"https://github.com/nodeca/js-yaml/commit/59423c6f8cdc78742ac00e25a4dd39ef16b702e4","tags":["x_refsource_MISC"]},{"url":"https://github.com/nodeca/js-yaml/releases/tag/3.15.0","name":"https://github.com/nodeca/js-yaml/releases/tag/3.15.0","tags":["x_refsource_MISC"]},{"url":"https://github.com/nodeca/js-yaml/releases/tag/4.3.0","name":"https://github.com/nodeca/js-yaml/releases/tag/4.3.0","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"HIGH","baseScore":7.5,"baseSeverity":"HIGH","confidentialityImpact":"NONE","integrityImpact":"NONE","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-407","lang":"en","description":"CWE-407: Inefficient Algorithmic Complexity","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-07-08T15:15:54.675Z"},"source":{"advisory":"GHSA-52cp-r559-cp3m","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","references":[{"url":"https://github.com/nodeca/js-yaml/security/advisories/GHSA-52cp-r559-cp3m","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-07-09T15:14:16.302841Z","id":"CVE-2026-59869","options":[{"Exploitation":"poc"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-07-09T15:14:29.753Z"}}]}}}