{"id":"CVE-2026-126066","state":"PUBLISHED","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.","publishedAt":"2026-11-10T20:23:16.019Z","updatedAt":"2026-11-10T20:23:16.019Z","severity":{"score":3.7,"label":"Low","version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L","source":"GitHub_M"},"assigner":"GitHub_M","products":["NaturalIntelligence fast-xml-parser"],"affected":[{"vendor":"NaturalIntelligence","product":"fast-xml-parser","versions":[{"version":"< 5.12.0","status":"affected"}]}],"references":["https://github.com/NaturalIntelligence/fast-xml-parser/security/advisories/GHSA-474x-hrwr-fgx4","https://github.com/NaturalIntelligence/fast-xml-parser/commit/0c3659348364959da62954b73728fb3bd05ebcb4","https://github.com/NaturalIntelligence/fast-xml-parser/releases/tag/v5.12.0"],"weaknesses":["CWE-407"],"ingestedAt":"2026-11-10T20:30:06.778Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/126xxx/CVE-2026-126066.json","commit":"56b6c26af892d89b485e301e3e32feb453abafc8","baselineCommit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-126066","state":"PUBLISHED","datePublished":"2026-11-10T20:23:16.019Z","dateUpdated":"2026-11-10T20:23:16.019Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-11-10T17:07:43.283Z"},"containers":{"cna":{"title":"fast-xml-parser: Quadratic CPU consumption scanning unterminated stop-node tags","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."}],"affected":[{"vendor":"NaturalIntelligence","product":"fast-xml-parser","versions":[{"version":"< 5.12.0","status":"affected"}]}],"references":[{"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","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/NaturalIntelligence/fast-xml-parser/commit/0c3659348364959da62954b73728fb3bd05ebcb4","name":"https://github.com/NaturalIntelligence/fast-xml-parser/commit/0c3659348364959da62954b73728fb3bd05ebcb4","tags":["x_refsource_MISC"]},{"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","tags":["x_refsource_MISC"]}],"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","lang":"en","description":"CWE-407: Inefficient Algorithmic Complexity","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-11-10T20:23:16.019Z"},"source":{"advisory":"GHSA-474x-hrwr-fgx4","discovery":"UNKNOWN"}}}}}