{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-111766", "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "state": "PUBLISHED", "assignerShortName": "GitHub_M", "dateReserved": "2026-10-16T17:52:09.082Z", "datePublished": "2026-10-19T19:47:46.488Z", "dateUpdated": "2026-10-19T19:47:46.488Z"}, "containers": {"cna": {"title": "markdown-it: Quadratic-time denial of service in inline HTML parsing with html enabled", "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"}]}], "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"}}], "references": [{"name": "https://github.com/markdown-it/markdown-it/security/advisories/GHSA-vfgh-jcmw-g37q", "tags": ["x_refsource_CONFIRM"], "url": "https://github.com/markdown-it/markdown-it/security/advisories/GHSA-vfgh-jcmw-g37q"}, {"name": "https://github.com/markdown-it/markdown-it/commit/928bc8c11ded60181c0e7fc5aa954eec582e8e79", "tags": ["x_refsource_MISC"], "url": "https://github.com/markdown-it/markdown-it/commit/928bc8c11ded60181c0e7fc5aa954eec582e8e79"}, {"name": "https://github.com/markdown-it/markdown-it/commit/d99f48839d37af6fd8a2617516c43dab90755503", "tags": ["x_refsource_MISC"], "url": "https://github.com/markdown-it/markdown-it/commit/d99f48839d37af6fd8a2617516c43dab90755503"}, {"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/14.3.3"}, {"name": "https://github.com/markdown-it/markdown-it/releases/tag/15.0.3", "tags": ["x_refsource_MISC"], "url": "https://github.com/markdown-it/markdown-it/releases/tag/15.0.3"}], "affected": [{"vendor": "markdown-it", "product": "markdown-it", "versions": [{"version": ">= 15.0.0, < 15.0.3", "status": "affected"}, {"version": "< 14.3.3", "status": "affected"}]}], "providerMetadata": {"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "shortName": "GitHub_M", "dateUpdated": "2026-10-19T19:47:46.488Z"}, "descriptions": [{"lang": "en", "value": "markdown-it is a Markdown parser. Prior to 14.3.3 and 15.0.3, when the html option or commonmark preset is enabled and the constructs occur inside a paragraph, attacker-controlled Markdown containing repeated unterminated inline HTML comments, processing instructions, declarations, or CDATA sections reaches src/rules_inline/html_inline.ts. Its HTML_TAG_RE match searches the remaining suffix for the appropriate terminator; when no terminator is present, parsing advances to the next opener and repeats the match over overlapping input, causing quadratic processing and denial of service through event-loop blocking or an unresponsive browser main thread. HTML blocks and the default HTML-disabled configuration are not affected by these payloads. This issue is fixed in versions 14.3.3 and 15.0.3."}], "source": {"advisory": "GHSA-vfgh-jcmw-g37q", "discovery": "UNKNOWN"}}}}

{}

{"affected": [{"affectedData": [{"product": "markdown-it", "vendor": "markdown-it", "versions": [{"status": "affected", "version": ">= 15.0.0, < 15.0.3"}, {"status": "affected", "version": "< 14.3.3"}]}], "source": "security-advisories@github.com"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "markdown-it is a Markdown parser. Prior to 14.3.3 and 15.0.3, when the html option or commonmark preset is enabled and the constructs occur inside a paragraph, attacker-controlled Markdown containing repeated unterminated inline HTML comments, processing instructions, declarations, or CDATA sections reaches src/rules_inline/html_inline.ts. Its HTML_TAG_RE match searches the remaining suffix for the appropriate terminator; when no terminator is present, parsing advances to the next opener and repeats the match over overlapping input, causing quadratic processing and denial of service through event-loop blocking or an unresponsive browser main thread. HTML blocks and the default HTML-disabled configuration are not affected by these payloads. This issue is fixed in versions 14.3.3 and 15.0.3."}], "id": "CVE-2026-111766", "lastModified": "2026-10-19T21:13:39.973", "metrics": {"cvssMetricV31": [{"cvssData": {"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"}, "exploitabilityScore": 2.2, "impactScore": 1.4, "source": "security-advisories@github.com", "type": "Secondary"}]}, "published": "2026-10-19T20:17:52.247", "references": [{"source": "security-advisories@github.com", "url": "https://github.com/markdown-it/markdown-it/commit/928bc8c11ded60181c0e7fc5aa954eec582e8e79"}, {"source": "security-advisories@github.com", "url": "https://github.com/markdown-it/markdown-it/commit/d99f48839d37af6fd8a2617516c43dab90755503"}, {"source": "security-advisories@github.com", "url": "https://github.com/markdown-it/markdown-it/releases/tag/14.3.3"}, {"source": "security-advisories@github.com", "url": "https://github.com/markdown-it/markdown-it/releases/tag/15.0.3"}, {"source": "security-advisories@github.com", "url": "https://github.com/markdown-it/markdown-it/security/advisories/GHSA-vfgh-jcmw-g37q"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Awaiting Analysis", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-400"}, {"lang": "en", "value": "CWE-407"}], "source": "security-advisories@github.com", "type": "Primary"}]}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[15.0.0,15.0.3)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[0,14.3.3)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "markdown-it", "source": "cna", "vendor": "markdown-it"}, "product": "markdown-it", "vendor": "markdown-it"}], "created": "2026-10-19T21:30:03.741087+00:00", "updated": "2026-10-19T21:30:03.741111+00:00", "vendors": ["markdown-it", "markdown-it$PRODUCT$markdown-it"]}