Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in Terry Lin WP Mermaid allows Stored XSS.This issue affects WP Mermaid: from n/a through 1.0.2.

Discourse Mermaid (discourse-mermaid-theme-component) allows users of Discourse, open-source forum software, to create graphs using the Mermaid syntax. Users of discourse-mermaid-theme-component version 1.0.0 who can create posts are able to inject arbitrary HTML on that post. The issue has been fixed on the `main` branch of the GitHub repository, with 1.1.0 named as a patched version. Admins can update the theme component through the admin UI. As a workaround, admins can temporarily disable discourse-mermaid-theme-component.

mdx-mermaid provides plug and play access to Mermaid in MDX. There is a potential for an arbitrary javascript injection in versions less than 1.3.0 and 2.0.0-rc1. Modify any mermaid code blocks with arbitrary code and it will execute when the component is loaded by MDXjs. This vulnerability was patched in version(s) 1.3.0 and 2.0.0-rc2. There are currently no known workarounds.

Mermaid is a JavaScript based diagramming and charting tool that uses Markdown-inspired text definitions and a renderer to create and modify complex diagrams. An attacker is able to inject arbitrary `CSS` into the generated graph allowing them to change the styling of elements outside of the generated graph, and potentially exfiltrate sensitive information by using specially crafted `CSS` selectors. The following example shows how an attacker can exfiltrate the contents of an input field by bruteforcing the `value` attribute one character at a time. Whenever there is an actual match, an `http` request will be made by the browser in order to "load" a background image that will let an attacker know what's the value of the character. This issue may lead to `Information Disclosure` via CSS selectors and functions able to generate HTTP requests. This also allows an attacker to change the document in ways which may lead a user to perform unintended actions, such as clicking on a link, etc. …

Mermaid is a Javascript based diagramming and charting tool that uses Markdown-inspired text definitions and a renderer to create and modify complex diagrams. Prior to version 8.13.8, malicious diagrams can run javascript code at diagram readers' machines. Users should upgrade to version 8.13.8 to receive a patch. There are no known workarounds aside from upgrading.

Mermaid before 8.11.0 allows XSS when the antiscript feature is used.

PHP remote file inclusion vulnerability in formdisp.php in the Mermaid 1.2 module for PHP-Nuke allows remote attackers to execute arbitrary PHP code via a URL in the module_name parameter.