{"id":"CVE-2026-115349","title":"Mistune 3.0.0 before 3.3.0 Denial of Service via Nested Bracket Parsing","summary":"Mistune from 3.0.0 before 3.3.0 contains an algorithmic complexity denial of service vulnerability in the parse_link_text function in src/mistune/helpers.py. Attackers can submit markdown with deeply nested square brackets triggering qua…","severity":"high","cvss":7.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","cvssSource":"cna","cwe":["CWE-1333"],"vendor":"lepture","product":"mistune","affected":["mistune >= 3.0.0 < 3.3.0"],"published":"2026-10-22","updated":"2026-10-22","sourceUpdated":"2026-10-22T19:13:26.171Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-115349","references":[{"url":"https://github.com/lepture/mistune/security/advisories/GHSA-3q64-rw38-243v","label":"GitHub Security Advisory (GHSA-3q64-rw38-243v)"},{"url":"https://www.vulncheck.com/advisories/mistune-3.0.0-before-3.3.0-denial-of-service-via-nested-bracket-parsing","label":"VulnCheck Advisory: Mistune 3.0.0 before 3.3.0 Denial of Service via Nested Bracket Parsing"}],"tags":["cve.org"],"ingestedAt":"2026-10-22T22:00:50.395Z","slug":"CVE-2026-115349","body":"## Overview\n\nMistune from 3.0.0 before 3.3.0 contains an algorithmic complexity denial of service vulnerability in the parse_link_text function in src/mistune/helpers.py. Attackers can submit markdown with deeply nested square brackets triggering quadratic parsing time, exhausting server CPU with small crafted requests.\n\n## Affected\n\n- `mistune >= 3.0.0 < 3.3.0`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":41,"depthScoreParts":{"impact":41.3,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}