CodiMD allows realtime collaborative markdown notes on all platforms. The notebook feature of Hackmd.io permits the rendering of iframe `HTML` tags with an improperly sanitized `name` attribute. This vulnerability enables attackers to perform cross-site scripting (XSS) attacks via DOM clobbering. This vulnerability is fixed in 2.5.4.
https://github.com/hackmdio/codimd/security/advisories/GHSA-22jv-vch8-2vp9