{"id":"CVE-2026-111758","state":"PUBLISHED","title":"markdown-it: Quadratic-time rendering of a single multi-line link reference definition with default options (regression since 14.0)","description":"markdown-it is a Markdown parser. From versions 14.1.0 to before 14.3.3, and 15.0.0 to before 15.0.3, a link reference definition whose label or title is never closed is O(n²) with default options. Continuation lines are pulled lazily with str += lineContent in src/rules_block/reference.ts, and the subsequent charCodeAt and slice calls flatten the V8 cons-string, copying everything collected so far; this runs before the rule decides the definition is invalid. No options are required to trigger it. This issue has been patched in versions 14.3.3 and 15.0.3.","publishedAt":"2026-10-20T20:28:40.677Z","updatedAt":"2026-10-28T16:40:33.483Z","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":["markdown-it markdown-it"],"affected":[{"vendor":"markdown-it","product":"markdown-it","versions":[{"version":">= 14.1.0, < 14.3.3","status":"affected"},{"version":">= 15.0.0, < 15.0.3","status":"affected"}]}],"references":["https://github.com/markdown-it/markdown-it/security/advisories/GHSA-gfr2-rv44-r23c","https://github.com/markdown-it/markdown-it/commit/48fbc465812c440020c663f040ab22deaf8f1eca","https://github.com/markdown-it/markdown-it/commit/d99f48839d37af6fd8a2617516c43dab90755503","https://github.com/markdown-it/markdown-it/releases/tag/14.3.3","https://github.com/markdown-it/markdown-it/releases/tag/15.0.3"],"weaknesses":["CWE-400","CWE-407"],"ingestedAt":"2026-10-29T20:10:33.477Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/111xxx/CVE-2026-111758.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-111758","state":"PUBLISHED","datePublished":"2026-10-20T20:28:40.677Z","dateUpdated":"2026-10-28T16:40:33.483Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-10-16T17:52:09.081Z"},"containers":{"cna":{"title":"markdown-it: Quadratic-time rendering of a single multi-line link reference definition with default options (regression since 14.0)","descriptions":[{"lang":"en","value":"markdown-it is a Markdown parser. From versions 14.1.0 to before 14.3.3, and 15.0.0 to before 15.0.3, a link reference definition whose label or title is never closed is O(n²) with default options. Continuation lines are pulled lazily with str += lineContent in src/rules_block/reference.ts, and the subsequent charCodeAt and slice calls flatten the V8 cons-string, copying everything collected so far; this runs before the rule decides the definition is invalid. No options are required to trigger it. This issue has been patched in versions 14.3.3 and 15.0.3."}],"affected":[{"vendor":"markdown-it","product":"markdown-it","versions":[{"version":">= 14.1.0, < 14.3.3","status":"affected"},{"version":">= 15.0.0, < 15.0.3","status":"affected"}]}],"references":[{"url":"https://github.com/markdown-it/markdown-it/security/advisories/GHSA-gfr2-rv44-r23c","name":"https://github.com/markdown-it/markdown-it/security/advisories/GHSA-gfr2-rv44-r23c","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/markdown-it/markdown-it/commit/48fbc465812c440020c663f040ab22deaf8f1eca","name":"https://github.com/markdown-it/markdown-it/commit/48fbc465812c440020c663f040ab22deaf8f1eca","tags":["x_refsource_MISC"]},{"url":"https://github.com/markdown-it/markdown-it/commit/d99f48839d37af6fd8a2617516c43dab90755503","name":"https://github.com/markdown-it/markdown-it/commit/d99f48839d37af6fd8a2617516c43dab90755503","tags":["x_refsource_MISC"]},{"url":"https://github.com/markdown-it/markdown-it/releases/tag/14.3.3","name":"https://github.com/markdown-it/markdown-it/releases/tag/14.3.3","tags":["x_refsource_MISC"]},{"url":"https://github.com/markdown-it/markdown-it/releases/tag/15.0.3","name":"https://github.com/markdown-it/markdown-it/releases/tag/15.0.3","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-400","lang":"en","description":"CWE-400: Uncontrolled Resource Consumption","type":"CWE"}]},{"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":"2026-10-20T20:28:40.677Z"},"source":{"advisory":"GHSA-gfr2-rv44-r23c","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","references":[{"url":"https://github.com/markdown-it/markdown-it/security/advisories/GHSA-gfr2-rv44-r23c","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-10-28T16:39:57.942731Z","id":"CVE-2026-111758","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":"2026-10-28T16:40:33.483Z"}}]}}}