{"id":"CVE-2026-86428","title":"commonmark versions from 1.5.0 before 2.10.0 contain a denial of service vulnerability in the AttributesExtension when processing distinctly-named attributes","summary":"commonmark versions from 1.5.0 before 2.10.0 contain a denial of service vulnerability in the AttributesExtension when processing distinctly-named attributes. Attackers can submit Markdown with numerous distinct attribute names to cause …","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","cwe":["CWE-407"],"vendor":"thephpleague","product":"commonmark","affected":["commonmark >= 1.5.0, < 2.10.0"],"patched":["commonmark 2.10.0"],"published":"2026-09-07","updated":"2026-09-09","sourceUpdated":"2026-09-09T16:31:45.987","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-86428","references":[{"url":"https://github.com/thephpleague/commonmark/security/advisories/GHSA-8rr7-cvq3-gmfh","label":"disclosure@vulncheck.com"},{"url":"https://www.vulncheck.com/advisories/commonmark-1.5.0-before-2.10.0-denial-of-service-via-attributes","label":"disclosure@vulncheck.com"}],"tags":["nvd","cve.org"],"epss":0.00493,"epssPercentile":0.39702,"ssvc":{"exploitation":"none","automatable":"yes","technicalImpact":"partial","timestamp":"2026-09-08T12:50:42.697699Z"},"ingestedAt":"2026-09-08T15:33:26.977Z","slug":"CVE-2026-86428","body":"## Overview\n\ncommonmark versions from 1.5.0 before 2.10.0 contain a denial of service vulnerability in the AttributesExtension when processing distinctly-named attributes. Attackers can submit Markdown with numerous distinct attribute names to cause quadratic-time attribute merging and filtering, consuming disproportionate CPU resources and preventing legitimate requests from completing.\n\n## Affected\n\n- `commonmark >= 1.5.0, < 2.10.0`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `commonmark 2.10.0`","depth":"twilight","depthScore":41,"depthScoreParts":{"impact":41.3,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}