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 and turns everything after it into a new CSS rule on the page. This enables page defacement, user tracking via url() callbacks, and DOM attribute exfiltration. 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 rendering the mermaid diagram in a sandboxed <iframe>.

fedora FEDORA-2026-5afe6630dc: nextcloud-33.0.6-1.fc43

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - 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 and turns everything after it into a new CSS rule on the page. This enables page     defacement, user tracking via url() callbacks, and DOM attribute exfiltration. 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 rendering the mermaid diagram in     a sandboxed <iframe>. (CVE-2026-41148)

Note that Nessus relies on the presence of the package as reported by the vendor.

There are packages installed that are affected by a vulnerability referenced in the following CVE:

  - 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 and turns everything after it into a new CSS rule on the page. This enables page
    defacement, user tracking via url() callbacks, and DOM attribute exfiltration. 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 rendering the mermaid diagram in
    a sandboxed <iframe>. (CVE-2026-41148)

ID	Name	Product	Family	Severity
316560	Linux Distros Unpatched Vulnerability : CVE-2026-41148	Nessus	Misc.	medium
441734	SCA: security update for mermaid (GHSA-xcj9-5m2h-648r)	Tenable Cloud Security	SCA Checks	medium
441734	SCA: security update for mermaid (GHSA-xcj9-5m2h-648r)	Tenable Self-Hosted Container Security	SCA Checks	medium

Detections

Analytics

CVE-2026-41148

medium

Tenable Plugins

Coming Soon

medium

medium

medium