Incorrect authorization in Etherpad - CVE-2026-55089
Published: September 22, 2026
Vulnerability identifier: #VU151597
CSH Severity: Medium
CVSS v4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:L/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-55089
CWE-ID: CWE-863
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to access all Etherpad HTTP API endpoints with administrator privileges.
The vulnerability exists due to improper authorization in APIHandler when validating JWTs issued through the OAuth authorization_code flow. A remote user can obtain a signed JWT with an admin claim set to false to access all Etherpad HTTP API endpoints with administrator privileges.
Only instances using an authentication method other than apikey and having a settings.users entry with is_admin explicitly set to false are affected.
Affected software
Etherpad
How to mitigate CVE-2026-55089
Install security update from vendor's website.
Etherpad - update to 3.1.0