Cross Site Scripting (XSS) vulnerability in Rendering Engine in jbt Markdown Editor thru commit 2252418c27dffbb35147acd8ed324822b8919477, allows remote attackers to execute arbirary code via crafted payload or opening malicious .md file.

The table extension in GitHub Flavored Markdown before version 0.29.0.gfm.1 takes O(n * n) time to parse certain inputs. An attacker could craft a markdown table which would take an unreasonably long time to process, causing a denial of service. This issue does not affect the upstream cmark project. The issue has been fixed in version 0.29.0.gfm.1.