{"action":"Upgrade league/commonmark to 2.9.0 or later.","affected":[{"fixed":"2.9.0","introduced":"2.0.0"}],"component":"league/commonmark","cve_ids":["CVE-2026-86434"],"ecosystem":"Packagist","exploited":false,"fixed_versions":["2.9.0"],"ghsa_id":"GHSA-mh25-x5hq-wrqp","id":"tcs_01M5JK7VWPQZ0Z1J3VY8N45FYN","modified_at":"2026-10-20T12:11:18.651252052Z","published_at":"2026-08-06T20:41:45Z","references":["https://osv.dev/vulnerability/GHSA-mh25-x5hq-wrqp","https://github.com/thephpleague/commonmark/security/advisories/GHSA-mh25-x5hq-wrqp","https://github.com/thephpleague/commonmark","https://github.com/thephpleague/commonmark/releases/tag/2.9.0"],"severity":{"label":"high","score":7.5},"sources":[{"source":"osv","source_id":"GHSA-mh25-x5hq-wrqp","url":"https://osv.dev/vulnerability/GHSA-mh25-x5hq-wrqp"}],"summary":"league/commonmark: Denial of service via colliding heading slugs"}