Is CVE-2026-105784 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-105784 being exploited in the wild.

How severe is CVE-2026-105784?

Medium severity, with a CVSS score of 4.6, published 6 October 2026.

Is there a fix for CVE-2026-105784?

Yes: fixed in 3.7.13. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-105784 attacked?

It is attacked with local access.

Am I affected by CVE-2026-105784?

Check whether you run Joplin at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-105784: Joplin CSS injection in whiteboard text and file nodes

CVE-2026-105784 · Severity: medium · CVSS 4.6 · Published 2026-10-06

Joplin, an open-source note-taking application, fails to sanitize Markdown content in its whiteboard editor, allowing malicious notes to inject CSS that modifies the application interface. An attacker who crafts a specially formatted note can alter the appearance of trusted UI elements, track when notes are opened, or potentially expose sensitive attribute values. The vulnerability cannot lead to code execution due to Content Security Policy protections, but still poses a security and usability risk.

Technologies: Joplin. Vendors: Joplin.

Quick answers

Is CVE-2026-105784 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-105784 being exploited in the wild.
How severe is CVE-2026-105784?: Medium severity, with a CVSS score of 4.6, published 6 October 2026.
Which products and versions are affected?: Joplin before 3.7.13.
Is there a fix for CVE-2026-105784?: Yes: fixed in 3.7.13. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-105784 attacked?: It is attacked with local access.
Am I affected by CVE-2026-105784?: Check whether you run Joplin at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

Fixed in: 3.7.13

Technical details

The vulnerability is a CSS injection flaw in the TextNode and FileNode components of the whiteboard editor. These components use dangerouslySetInnerHTML to render Markdown-formatted content without stripping style elements and remote CSS imports, allowing arbitrary CSS to be injected into the main application document. An attacker must craft a malicious note containing a jsoncanvas fence block; no authentication or special user interaction is required beyond opening the note. CSP blocks inline script execution, limiting the impact to CSS-based attacks like UI redressing and exfiltration via CSS attribute selectors.

Affected products

Joplin Joplin before 3.7.13

Timeline

2026-10-06: disclosed
2026-08-22: patched: Fix committed prior to disclosure

References

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