{"id":"CVE-2019-25781","aliases":[],"cve":{"records":[{"id":"CVE-2019-25781","source":"VulnCheck","state":"PUBLISHED","reasons":[],"replacements":[],"disputed":false,"unsupportedWhenAssigned":false,"reserved":"2026-10-29T11:51:49.648Z","published":"2026-10-29T13:08:49.597Z","modified":"2026-10-29T13:08:49.597Z"}],"publishers":[{"name":"VulnCheck","role":"CNA","organizationId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","modified":"2026-10-29T13:08:49.597Z"}],"references":[{"url":"https://github.com/Python-Markdown/markdown/issues/798","tags":["issue-tracking"],"source":"VulnCheck"},{"url":"https://github.com/Python-Markdown/markdown","tags":["product"],"source":"VulnCheck"},{"url":"https://github.com/Python-Markdown/markdown/issues/1654","tags":["issue-tracking"],"source":"VulnCheck"},{"url":"https://github.com/Python-Markdown/markdown/blob/b41e0aaf1181f1a8cb200cf5a815aad7c0020d23/markdown/inlinepatterns.py#L1155-L1172","tags":["technical-description"],"source":"VulnCheck"},{"url":"https://www.vulncheck.com/advisories/python-markdown-3.0-through-3.11.2-denial-of-service-via-link-bracket-parsing","tags":["third-party-advisory"],"source":"VulnCheck"}],"weaknesses":[{"id":"CWE-407","description":"Inefficient Algorithmic Complexity","source":"VulnCheck"}],"applicability":[{"source":"VulnCheck","statements":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:a:python-markdown2_project:python-markdown2:*:*:*:*:*:*:*:*","versionStartIncluding":"3.0","versionEndIncluding":"3.11.2"}]}]}]}],"prioritization":[]},"title":"Python-Markdown 3.0 through 3.11.2 Denial of Service via Link Bracket Parsing","titleSource":"VulnCheck","descriptionSource":"VulnCheck","description":"Python-Markdown 3.0 through 3.11.2 contains an algorithmic complexity vulnerability in inline link parsing that allows remote attackers to exhaust CPU through unmatched brackets. Attackers can submit short Markdown containing repeated [ or ![ characters, forcing LinkInlineProcessor.getText() and getLink() into quadratic scans that keep workers busy for minutes.","score":8.7,"severity":"high","published":"2026-10-29T13:08:49.597Z","modified":"2026-10-29T13:08:49.597Z","withdrawn":false,"knownExploited":false,"affected":[],"products":[{"vendor":"Python-Markdown","name":"Markdown","platforms":[],"versions":[{"version":"3.0","status":"affected","lessThanOrEqual":"3.11.2","versionType":"custom"}],"defaultStatus":"unaffected","packageURL":"pkg:pypi/markdown","packageIdentity":{"ecosystem":"PyPI","name":"markdown"},"cpes":[],"source":"VulnCheck","url":"https://www.cve.org/CVERecord?id=CVE-2019-25781"}],"remediation":[],"references":["https://github.com/Python-Markdown/markdown/issues/798","https://github.com/Python-Markdown/markdown","https://github.com/Python-Markdown/markdown/issues/1654","https://github.com/Python-Markdown/markdown/blob/b41e0aaf1181f1a8cb200cf5a815aad7c0020d23/markdown/inlinepatterns.py#L1155-L1172","https://www.vulncheck.com/advisories/python-markdown-3.0-through-3.11.2-denial-of-service-via-link-bracket-parsing"],"sources":[{"name":"CVE","id":"CVE-2019-25781","modified":"2026-10-29T13:08:49.597Z","url":"https://www.cve.org/CVERecord?id=CVE-2019-25781"}],"assessments":[{"source":"VulnCheck","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","score":8.7},{"source":"VulnCheck","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","score":7.5}],"sourceAffected":[],"observedAt":"2026-10-29T14:05:07.399Z","kev":{"status":"not-listed","checkedAt":"2026-10-31T14:00:31.626Z"},"coverage":[{"source":"NVD","status":"not-checked"},{"source":"GHSA","status":"not-checked"},{"source":"EUVD","status":"not-checked"},{"source":"EPSS","status":"not-checked"}],"evidence":[],"aiSummary":{"text":"Python-Markdown versions 3.0 through 3.11.2 contain an algorithmic complexity vulnerability in inline link parsing, allowing attackers to exhaust CPU through unmatched brackets. Attackers can submit short Markdown containing repeated [ or ![ characters. This forces LinkInlineProcessor into quadratic scans, keeping workers busy for minutes.","model":"@cf/meta/llama-3.3-70b-instruct-fp8-fast","generatedAt":"2026-10-30T09:10:57.334Z","sources":[{"name":"CVE","url":"https://www.cve.org/CVERecord?id=CVE-2019-25781"}]}}