Hubzilla up to 11.2.1 OAuth2 Authorization Endpoint post client_id/client_secret/redirect_uri/scope cross-site request forgery

Summaryinfo

A vulnerability labeled as problematic has been found in Hubzilla up to 11.2.1. This affects the function Zotlabs\Module\Authorize::post of the component OAuth2 Authorization Endpoint. Such manipulation of the argument client_id/client_secret/redirect_uri/scope leads to cross-site request forgery. This vulnerability is traded as CVE-2026-70556. The attack may be launched remotely. There is no exploit available.

Detailsinfo

A vulnerability was found in Hubzilla up to 11.2.1 and classified as problematic. Affected by this issue is the function Zotlabs\Module\Authorize::post of the component OAuth2 Authorization Endpoint. The manipulation of the argument client_id/client_secret/redirect_uri/scope with an unknown input leads to a cross-site request forgery vulnerability. Using CWE to declare the problem leads to CWE-352. The web application does not, or can not, sufficiently verify whether a well-formed, valid, consistent request was intentionally provided by the user who submitted the request. Impacted is integrity. CVE summarizes:

Hubzilla 11.2.1 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.

The advisory is shared for download at framagit.org. This vulnerability is handled as CVE-2026-70556 since 08/04/2026. The exploitation is known to be easy. The attack may be launched remotely. No form of authentication is required for exploitation. Successful exploitation requires user interaction by the victim. There are known technical details, but no exploit is available.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

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Name

• Hubzilla

Version

• 11.2.0
• 11.2.1

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