Mermaid is a JavaScript tool that uses Markdown-inspired text to create and modify diagrams and charts. From version 11.6.0 until 11.16.1, Mermaid Radar Diagrams allow arbitrary large values for the ticks parameter, which can cause high CPU usage and freeze the rendering webpage or JavaScript process for long periods of time, potentially until the process is killed from memory exhaustion. This issue is fixed in version 11.16.1.
Mermaid is a JavaScript tool that uses Markdown-inspired text to create and modify diagrams and charts. Prior to 10.9.8 and 11.16.1, Mermaid's configuration setters (mermaid.initialize, mermaidAPI.setConfig, and mermaidAPI.updateSiteConfig) merge caller-supplied configuration into Mermaid's internal config using the assignWithDepth deep-merge helper, which is vulnerable to prototype pollution. This is only exploitable if an application forwards untrusted data directly into one of these configuration entry points, which is outside their documented usage; diagram-supplied configuration (e.g. %%{init: {}}%% or YAML frontmatter) is not affected.
Mermaid allows CSS injection applying to sibling elements of the diagram
Mermaid is a JavaScript tool that uses Markdown-inspired text to create and modify diagrams and charts. Prior to 10.9.8 and 11.16.1, Mermaid is vulnerable to CSS injection via sibling combinator selectors generated from diagram-supplied class or id names. An attacker who can supply diagram text can inject arbitrary CSS into the rendered page, potentially altering the appearance or behavior of unrelated page elements. This issue is fixed in versions 10.9.8 and 11.16.1.
Mermaid Architecture diagrams are vulnerable to prototype pollution
Mermaid is a JavaScript tool that uses Markdown-inspired text to create and modify diagrams and charts. From version 11.5.0 until 11.16.1, Mermaid Architecture Diagrams are vulnerable to prototype pollution when a diagram defines a group with an id of __proto__. Because the group id is used directly as an object property key without validation, an attacker who can supply diagram text can pollute Object.prototype, potentially affecting the behavior of the embedding application. This issue is fixed in version 11.16.1.
Mermaid XY Charts are vulnerable to an infinite loop DoS
Mermaid is a JavaScript tool that uses Markdown-inspired text to create and modify diagrams and charts. From version 10.6.0 until 10.9.8 and 11.16.1, Mermaid XY Charts are vulnerable to an infinite loop denial of service in the setXAxisRangeData function when configuring an X-Axis with invalid parameters. Because each loop iteration appends an element to an array, this generally causes a RangeError to appear after a few seconds, but it may instead cause the page or JavaScript process to crash from memory exhaustion, depending on the environment. This issue is fixed in versions 10.9.8 and 11.16.1.
Mermaid Gantt Charts are vulnerable to an Infinite Loop DoS
Mermaid is a JavaScript tool that uses Markdown-inspired text to create and modify diagrams and charts. Prior to 10.9.6 and 11.15.0, there is a denial-of-service attack when rendering gantt charts, if they use the excludes attribute to exclude all dates. mermaid.parse is unaffected, unless you then call the ganttDb.getTasks() (which is called when rendering a diagram). This vulnerability is fixed in 10.9.6 and 11.15.0.
Mermaid: Improper sanitization of configuration leads to CSS injection
Mermaid is a JavaScript tool that uses Markdown-inspired text to create and modify diagrams and charts. Prior to 10.9.6 and 11.15.0, Mermaid's default configuration allows injecting CSS that applies outside of the Mermaid diagram via the fontFamily, themeCSS, and altFontFamily configuration options. The injected CSS exploits stylis's & (scope reference) handling. :not(&) escapes the #mermaid-xxx automatic scoping, applying styles to all page elements. Global at-rules (@font-face, @keyframes, @counter-style) are also injectable as stylis hoists them to top level. This allows page defacement and DOM attribute exfiltration via CSS :has() select
Mermaid: Improper sanitization of `classDef` in state diagrams leads to HTML injection
Mermaid is a JavaScript tool that uses Markdown-inspired text to create and modify diagrams and charts. Versions 10.9.5 and earlier, as well as 11.0.0-alpha.1 through 11.14.0, are vulnerable to HTML injection under the default configuration. Specifically, the classDef directive in Mermaid state diagrams permits DOM injection that escapes the SVG context. However, <script> tags are stripped, which prevents cross-site scripting (XSS). This issue has been fixed in versions 10.9.6 and 11.15.0. If developers are unable to immediately upgrade, they can work around this issue by setting "securityLevel": "sandbox", which prevents the issue by renderi
Mermaid: Improper sanitization of `classDefs` in diagrams leads to CSS injection
Mermaid is a JavaScript tool that uses Markdown-inspired text to create and modify diagrams and charts. Versions 10.9.5 and prior, in addition to 11.0.0-alpha.1 through 11.12.0 are vulnerable to CSS injection through improper sanitization. The state diagram (and any other diagram type that routes user-controlled style strings through the createCssStyles parser) captures classDef values using an unrestricted regex that matches everything up to a newline. That value then flows unsanitized through addStyleClass() into createCssStyles() and is assigned to style.innerHTML, so a closing brace (}) in the value terminates the generated CSS selector a
Mermaid improperly sanitizes of sequence diagram labels leading to XSS
Mermaid is a JavaScript based diagramming and charting tool that uses Markdown-inspired text definitions and a renderer to create and modify complex diagrams. In the default configuration of mermaid 10.9.0-rc.1 to 11.9.0, user supplied input for sequence diagram labels is passed to innerHTML during calculation of element size, causing XSS.
Mermaid does not properly sanitize architecture diagram iconText leading to XSS
Mermaid is a JavaScript based diagramming and charting tool that uses Markdown-inspired text definitions and a renderer to create and modify complex diagrams. In the default configuration of mermaid 11.9.0 and earlier, user supplied input for architecture diagram icons is passed to the d3 html() method, creating a sink for cross site scripting. This vulnerability is fixed in 11.10.0.
Prototype pollution vulnerability found in Mermaid's bundled version of DOMPurify
The following bundled files within the Mermaid NPM package contain a bundled version of DOMPurify that is vulnerable to https://github.com/cure53/DOMPurify/security/advisories/GHSA-mmhx-hmjr-r674, potentially resulting in an XSS attack.
This affects the built:
- `dist/mermaid.min.js`
- `dist/mermaid.js`
- `dist/mermaid.esm.mjs`
- `dist/mermaid.esm.min.mjs`
This will also affect users that use the above files via a CDN link, e.g. `https://cdn.jsdelivr.net/npm/[email protected]/dist/mermaid.min.js`
**Users that use the default NPM export of `mermaid`, e.g. `import mermaid from 'mermaid'`, or the `dist/mermaid.core.mjs` file, do not use this bu
Arbitrary `CSS` injection into the generated graph affecting the container HTML in mermaid.js
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 "
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.
Versions of `mermaid` prior to 8.2.3 are vulnerable to Cross-Site Scripting. If malicious input such as `A["<img src=invalid onerror=alert('XSS')></img>"] ` is provided to the application, it will execute the code instead of rendering it as text due to improper output encoding.
## Recommendation
Upgrade to version 8.2.3 or later