Thephpleague: >> Commonmark >> 0.7.2 Security Vulnerabilities
league/commonmark is a PHP Markdown parser. Prior to version 2.8.1, the DisallowedRawHtml extension can be bypassed by inserting a newline, tab, or other ASCII whitespace character between a disallowed HTML tag name and the closing >. For example, <script\n> would pass through unfiltered and be rendered as a valid HTML tag by browsers. This is a cross-site scripting (XSS) vector for any application that relies on this extension to sanitize untrusted user input. All applications using the DisallowedRawHtml extension to process untrusted markdown are affected. Applications that use a dedicated HTML sanitizer (such as HTML Purifier) on the rendered output are not affected. This issue has been patched in version 2.8.1.
CVSS Score
6.1
EPSS Score
0.0
Published
2026-03-07
Cross-site scripting (XSS) vulnerability in the PHP League CommonMark library before 0.18.3 allows remote attackers to insert unsafe links into HTML by using double-encoded HTML entities that are not properly escaped during rendering, a different vulnerability than CVE-2018-20583.
CVSS Score
6.1
EPSS Score
0.003
Published
2019-03-24