SB2026101241 - Incorrect authorization in Etherpad

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Main Vulnerability Database SB2026101241

SB2026101241 - Incorrect authorization in Etherpad

Published: October 12, 2026

Security Bulletin ID SB2026101241
CSH Severity
Medium
Patch available
YES
Number of vulnerabilities 1
Exploitation vector Remote access
Highest impact Code execution

Breakdown by Severity

Medium 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 1 vulnerability.


1) Incorrect authorization (CVE-ID: N/A)

CWE-ID: CWE-863 - Incorrect Authorization

CVSSv4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]


The vulnerability allows a remote user to gain full administrative access to the HTTP API.

The vulnerability exists due to incorrect authorization in the HTTP API handler (APIHandler.ts) when validating bearer JWTs. A remote user can submit an ordinary authorization_code token whose sub claim matches a configured client_id, causing the token to be treated as a client_credentials token and bypass the admin claim check, to gain full administrative access to the HTTP API.

Only instances using Etherpad's built-in OIDC provider with configured API clients are affected.


Remediation

Install update from vendor's website.

References