Disclosure summary
Showdown through 2.1.0 contains a cross-site scripting vulnerability in the makehtml link and image subparsers, which fail to escape double quotes in destination URLs placed into href and src attributes. Attackers can craft markdown links or images containing a double quote followed by onerror or onmouseover handlers to execute script when victims view rendered HTML.
Source-reported weakness categories
CWE-79
Source-specific records & product guidance
Sources retain their own attribution and scoring. Follow the original record to confirm affected versions, fixed releases, and configuration conditions.
NIST National Vulnerability Database · NVD-CVE-2026-104477
Open original source · Updated Oct 05, 2026
Only CPE matches marked vulnerable=true are indexed. AND/OR platform conditions must be checked in the original NVD record.
Original records & references
PUBLISHED 2026-10-02T20:16:35-04:00
MODIFIED 2026-10-05T17:16:32-04:00
INGESTED 2026-10-06T11:45:30-04:00