CVE-2026-30838

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, would pass through unfiltered and be rendered as a...

Cross-site Scripting (XSS)

Overview league/commonmark is a PHP-based Markdown parser which supports the full CommonMark spec. It is based on the CommonMark JS reference implementation. Affected versions of this package are vulnerable to Cross-site Scripting XSS via the DisallowedRawHtml extension when a newline, tab, or...

CVE-2026-30838

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, would pass through unfiltered and be rendered as a...

DEBIAN-CVE-2026-30838

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, would pass through unfiltered and be rendered as a...

UBUNTU-CVE-2026-30838

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, would pass through unfiltered and be rendered as a...

CVE-2026-30838

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, would pass through unfiltered and be rendered as a...

CVE-2026-30838 league/commonmark: DisallowedRawHtml extension bypass via whitespace in HTML tag names

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, would pass through unfiltered and be rendered as a...

CVE-2026-30838 league/commonmark: DisallowedRawHtml extension bypass via whitespace in HTML tag names

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, would pass through unfiltered and be rendered as a...

CVE-2026-30838

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, would pass through unfiltered and be rendered as a...

CVE-2026-30838 league/commonmark: DisallowedRawHtml extension bypass via whitespace in HTML tag names

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, would pass through unfiltered and be rendered as a...

CVE-2026-30838

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, would pass through unfiltered and be rendered as a...

CVE-2026-30838

CVE-2026-30838 affects league/commonmark, a PHP Markdown parser. Prior to version 2.8.1, the DisallowedRawHtml extension can be bypassed by inserting ASCII whitespace between a disallowed HTML tag name and the closing >, e.g., , enabling a cross-site scripting (XSS) vector for applications tha...

CommonMark has DisallowedRawHtml extension bypass via whitespace in HTML tag names

Impact 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, would pass through unfiltered and be rendered as a valid HTML tag by browsers. This is a cross-site scripting X...

PT-2026-23795

Name of the Vulnerable Software and Affected Versions league/commonmark versions prior to 2.8.1 Description The DisallowedRawHtml extension in league/commonmark can be bypassed by inserting ASCII whitespace characters between a disallowed HTML tag name and the closing ''. For example, would pass...