CVE-2026-59814 Joplin: Stored XSS via inline-served note attachment on published shares
Attackers can inject scripts via malicious attachments in shared notes, allowing session hijacking and data theft on Joplin Server.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-59814?
CVE-2026-59814 is a high-severity cross-site scripting vulnerability in laurent22 joplin, published on 21 Sep 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Official description
Joplin is an open source note-taking and to-do application that organises notes and lists into notebooks. Prior to 3.7.7, Joplin Server's GET /shares/:id?resource_id= route serves a resource with the attacker-controlled mime value and omits Content-Disposition when the resource title is empty. A low-privileged user can publish an empty-title image/svg+xml attachment whose script executes when a victim opens the public share. By default, user content shares the Joplin Server application origin, allowing the script to access same-origin data and, when the victim is authenticated, perform actions with the victim's session, including reading administrative data and anti-CSRF tokens. Installations that configure USER_CONTENT_BASE_URL to a separate origin still execute the script, but on that separate user-content origin rather than the application origin. This issue is fixed in version 3.7.7.
Weakness: CWE-79
Which versions are affected by CVE-2026-59814?
How do I fix CVE-2026-59814?
No fix has been published for CVE-2026-59814 yet. Limit exposure of the affected software until one is available.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-59814 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-59814 exists.
Sources
Also known as GHSA-mx98-7h4g-6gmh.