Showdown through 2.1.0 XSS via unescaped quote in href and src attributes
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.
CVE-2026-104477
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-104477
showdown
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"vendor": "showdownjs",
"product": "showdown",
"versions": [
{
"status": "affected",
"version": "0",
"versionType": "semver",
"lessThanOrEqual": "2.1.0"
}
],
"packageURL": "pkg:npm/showdown",
"defaultStatus": "unaffected"
}
]- Related CVEs
- CVE-2026-104477
Source reference:
/cveMetadata/cveId
Publisher severity
medium
Source reference: /containers/cna/metrics
- Event
- #8933 · Revision 1
- Added to Heist Feed
- Publisher date