CVE intelligence and bounded remediation
CVE-2025-27134 — Joplin is a free, open source note taking and to-do application, which can handle a large number of notes organised into notebooks
Joplin is a free, open source note taking and to-do application, which can handle a large number of notes organised into notebooks. Prior to version 3.3.3, a privilege escalation vulnerability exists in the Joplin server, allowing non-admin users to exploit the API endpoint `PATCH /api/users/:id` to set the `is_admin` field to 1. The vulnerability allows malicious low-privileged users to perform administrative actions without proper authorization. This issue has been patched in version 3.3.3.
- Severity
- High
- CVSS
- 8.8 (3.1)
- Published
- 2025-04-30
- CISA KEV
- Not currently listed
- Ecosystem
- software/application
- Weaknesses
- CWE-284
Affected products
- joplin_project / joplin
Matched remediation archetype
Authorization bypass, IDOR, and cross-tenant access
This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.
Check exposure
- Map object and action authorization checks across API, UI, batch, import/export, and background-job paths.
- Identify tenant, ownership, role, and policy boundaries for affected resources and administrative operations.
- Use synthetic fixtures to compare intended access matrices without accessing another user's real data.
Remediate safely
- Enforce server-side authorization at each resource access and state transition using the authenticated principal and trusted tenant context.
- Scope data queries by tenant and ownership; treat client-supplied identifiers, roles, and policy claims as untrusted.
- Add deny-by-default policy tests for horizontal and vertical access across every affected transport.
Authoritative sources
Complete CVE record and remediation plan
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