{"api_version":"1","generated_at":"2026-11-11T06:33:09+00:00","cve":"CVE-2026-126066","urls":{"html":"https://cve.report/CVE-2026-126066","api":"https://cve.report/api/cve/CVE-2026-126066.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-126066","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-126066"},"summary":{"title":"fast-xml-parser: Quadratic CPU consumption scanning unterminated stop-node tags","description":"fast-xml-parser allows users to process XML from JS object without C/C++ based libraries or callbacks. Prior to 5.12.0, when the non-default stopNodes option is enabled, readStopNodeData() in OrderedObjParser.js calls readTagExp() for each less-than character in an unterminated stop-node body and repeatedly rescans the remaining input while looking for a closing greater-than character. An attacker who supplies XML containing many tag fragments without a later closing character can cause quadratic rescanning before parsing fails, blocking a Node.js event loop and causing CPU-exhaustion denial of service. This issue is fixed in version 5.12.0.","state":"PUBLISHED","assigner":"GitHub_M","published_at":"2026-11-10 21:19:24","updated_at":"2026-11-10 21:19:24"},"problem_types":["CWE-407","CWE-407 CWE-407: Inefficient Algorithmic Complexity"],"metrics":[{"version":"3.1","source":"security-advisories@github.com","type":"Secondary","score":"3.7","severity":"LOW","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L","data":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L","baseScore":3.7,"baseSeverity":"LOW","attackVector":"NETWORK","attackComplexity":"HIGH","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"LOW"}},{"version":"3.1","source":"CNA","type":"DECLARED","score":"3.7","severity":"LOW","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L","data":{"attackComplexity":"HIGH","attackVector":"NETWORK","availabilityImpact":"LOW","baseScore":3.7,"baseSeverity":"LOW","confidentialityImpact":"NONE","integrityImpact":"NONE","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L","version":"3.1"}}],"references":[{"url":"https://github.com/NaturalIntelligence/fast-xml-parser/releases/tag/v5.12.0","name":"https://github.com/NaturalIntelligence/fast-xml-parser/releases/tag/v5.12.0","refsource":"security-advisories@github.com","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://github.com/NaturalIntelligence/fast-xml-parser/commit/0c3659348364959da62954b73728fb3bd05ebcb4","name":"https://github.com/NaturalIntelligence/fast-xml-parser/commit/0c3659348364959da62954b73728fb3bd05ebcb4","refsource":"security-advisories@github.com","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://github.com/NaturalIntelligence/fast-xml-parser/security/advisories/GHSA-474x-hrwr-fgx4","name":"https://github.com/NaturalIntelligence/fast-xml-parser/security/advisories/GHSA-474x-hrwr-fgx4","refsource":"security-advisories@github.com","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-126066","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-126066","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"NaturalIntelligence","product":"fast-xml-parser","version":"affected < 5.12.0","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"product":"fast-xml-parser","vendor":"NaturalIntelligence","versions":[{"status":"affected","version":"< 5.12.0"}]}],"descriptions":[{"lang":"en","value":"fast-xml-parser allows users to process XML from JS object without C/C++ based libraries or callbacks. Prior to 5.12.0, when the non-default stopNodes option is enabled, readStopNodeData() in OrderedObjParser.js calls readTagExp() for each less-than character in an unterminated stop-node body and repeatedly rescans the remaining input while looking for a closing greater-than character. An attacker who supplies XML containing many tag fragments without a later closing character can cause quadratic rescanning before parsing fails, blocking a Node.js event loop and causing CPU-exhaustion denial of service. This issue is fixed in version 5.12.0."}],"metrics":[{"cvssV3_1":{"attackComplexity":"HIGH","attackVector":"NETWORK","availabilityImpact":"LOW","baseScore":3.7,"baseSeverity":"LOW","confidentialityImpact":"NONE","integrityImpact":"NONE","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-407","description":"CWE-407: Inefficient Algorithmic Complexity","lang":"en","type":"CWE"}]}],"providerMetadata":{"dateUpdated":"2026-11-10T20:23:16.019Z","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","shortName":"GitHub_M"},"references":[{"name":"https://github.com/NaturalIntelligence/fast-xml-parser/security/advisories/GHSA-474x-hrwr-fgx4","tags":["x_refsource_CONFIRM"],"url":"https://github.com/NaturalIntelligence/fast-xml-parser/security/advisories/GHSA-474x-hrwr-fgx4"},{"name":"https://github.com/NaturalIntelligence/fast-xml-parser/commit/0c3659348364959da62954b73728fb3bd05ebcb4","tags":["x_refsource_MISC"],"url":"https://github.com/NaturalIntelligence/fast-xml-parser/commit/0c3659348364959da62954b73728fb3bd05ebcb4"},{"name":"https://github.com/NaturalIntelligence/fast-xml-parser/releases/tag/v5.12.0","tags":["x_refsource_MISC"],"url":"https://github.com/NaturalIntelligence/fast-xml-parser/releases/tag/v5.12.0"}],"source":{"advisory":"GHSA-474x-hrwr-fgx4","discovery":"UNKNOWN"},"title":"fast-xml-parser: Quadratic CPU consumption scanning unterminated stop-node tags"}},"cveMetadata":{"assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","assignerShortName":"GitHub_M","cveId":"CVE-2026-126066","datePublished":"2026-11-10T20:23:16.019Z","dateReserved":"2026-11-10T17:07:43.283Z","dateUpdated":"2026-11-10T20:23:16.019Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-11-10 21:19:24","lastModifiedDate":"2026-11-10 21:19:24","problem_types":["CWE-407","CWE-407 CWE-407: Inefficient Algorithmic Complexity"],"metrics":{"cvssMetricV31":[{"source":"security-advisories@github.com","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L","baseScore":3.7,"baseSeverity":"LOW","attackVector":"NETWORK","attackComplexity":"HIGH","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"LOW"},"exploitabilityScore":2.2,"impactScore":1.4}]},"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"126066","Ordinal":"1","Title":"fast-xml-parser: Quadratic CPU consumption scanning unterminated","CVE":"CVE-2026-126066","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"126066","Ordinal":"1","NoteData":"fast-xml-parser allows users to process XML from JS object without C/C++ based libraries or callbacks. Prior to 5.12.0, when the non-default stopNodes option is enabled, readStopNodeData() in OrderedObjParser.js calls readTagExp() for each less-than character in an unterminated stop-node body and repeatedly rescans the remaining input while looking for a closing greater-than character. An attacker who supplies XML containing many tag fragments without a later closing character can cause quadratic rescanning before parsing fails, blocking a Node.js event loop and causing CPU-exhaustion denial of service. This issue is fixed in version 5.12.0.","Type":"Description","Title":"fast-xml-parser: Quadratic CPU consumption scanning unterminated"}]}}}