Versions of showdown prior to 1.9.1 are vulnerable to Reverse Tabnabbing. The package uses target='_blank' in anchor tags, allowing attackers to access window.opener for the original page when opening links. This is commonly used for phishing attacks.
Upgrade to version 1.9.1 or later.
{
"cwe_ids": [
"CWE-1022"
],
"github_reviewed": true,
"github_reviewed_at": "2020-08-31T18:54:24Z",
"nvd_published_at": null,
"severity": "LOW"
}