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Medium

Showdown through 2.1.0 XSS via unescaped quote in href and src attributes

Type: advisorySource: Official CVE List1 source record

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.

Announced Source revision 1
Original source ↗

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
Read the original announcement