CVE-2026-70556: Hubzilla

Medium severity, CVSS 4.3. EPSS: 0.2% chance of exploitation in the next 30 days.

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.

Affected products

• Hubzilla Hubzilla: before 11.4 (fixed in 11.4)

Published 2026-08-06. Last modified 2026-09-24.