CVE-2026-70556
Severity CVSS v4.0:
MEDIUM
Type:
CWE-352
Cross-Site Request Forgery (CSRF)
Publication date:
06/08/2026
Last modified:
13/08/2026
Description
Hubzilla versions prior to 11.4 contains a cross-site request forgery vulnerability in the OAuth2 /authorize endpoint handled by Zotlabs\Module\Authorize::post() that allows unauthenticated attackers to register arbitrary OAuth2 applications under an authenticated user's account by submitting a cross-origin POST request without CSRF token or Origin/Referer validation. Attackers can craft a malicious HTML form that autosubmits attacker-chosen OAuth2 parameters including client_id, client_secret, redirect_uri, and scope to silently register a persistent OAuth2 application, enabling interception of future OAuth2 authorization codes when the victim later authenticates against the attacker-controlled client.
Impact
Base Score 4.0
5.10
Severity 4.0
MEDIUM
Base Score 3.x
4.30
Severity 3.x
MEDIUM
References to Advisories, Solutions, and Tools
- https://framagit.org/hubzilla/core
- https://framagit.org/hubzilla/core/-/blob/dev/Zotlabs/Module/Authorize.php?ref_type=heads#L49
- https://hub.volse.no/cloud/harald/Skjermopptak_20260616_095037.webm
- https://www.vulncheck.com/advisories/hubzilla-csrf-via-oauth2-authorize-endpoint-app-registration
- https://hub.volse.no/cloud/harald/Skjermopptak_20260616_095037.webm



