{"action":"Upgrade @ckeditor/ckeditor5-markdown-gfm to 25.0.0 or later.","affected":[{"fixed":"25.0.0","introduced":"0"}],"component":"@ckeditor/ckeditor5-markdown-gfm","cve_ids":["CVE-2021-21254"],"ecosystem":"npm","epss":0.01814,"exploited":false,"fixed_versions":["25.0.0"],"ghsa_id":"GHSA-hgmg-hhc8-g5wr","id":"tcs_01M5KFV36R0BV003PTP3P1JYW4","modified_at":"2026-07-08T06:29:35.375771949Z","published_at":"2021-01-29T21:51:22Z","references":["https://osv.dev/vulnerability/GHSA-hgmg-hhc8-g5wr","https://github.com/ckeditor/ckeditor5/security/advisories/GHSA-hgmg-hhc8-g5wr","https://nvd.nist.gov/vuln/detail/CVE-2021-21254","https://github.com/ckeditor/ckeditor5","https://github.com/ckeditor/ckeditor5/releases/tag/v25.0.0","https://www.npmjs.com/package/@ckeditor/ckeditor5-markdown-gfm"],"severity":{"label":"medium","score":6.5},"sources":[{"source":"osv","source_id":"GHSA-hgmg-hhc8-g5wr","url":"https://osv.dev/vulnerability/GHSA-hgmg-hhc8-g5wr"}],"summary":"CKEditor 5 Markdown plugin Regular expression Denial of Service"}