Pixelfed vulnerabilities

Vulnerability in Pixelfed up to 0.12.11 affects the instancePeers function in app/Http/Controllers/Api/ApiV1Controller.php of the OAuth Scope Handler component. Manipulation of the ID argument leads to missing authentication. The attack can be remote, and the exploit is public. Upgrading to 0.12.10 is recommended (though description says 0.12.11, recommended is 0.12.10 – likely a typo).

Pixelfed through 0.12.9 fails to validate follower status in StoryComposeController react and comment endpoints, allowing authenticated users to access follower-only stories. Attackers can enumerate sequential story IDs and submit reactions or comments to retrieve story media URLs and author information without following the account.

Pixelfed's SearchController (behind the auth middleware) accepts a URL via its remote-search parameters and fetches it server-side through ActivityPubFetchService, whose validateUrl only blocks the literal hosts 127.0.0.1, localhost, and ::1 and requires https, without checking the resolved IP against private, internal, or link-local ranges (e.g. 169.254.169.254).