SourceHut's closed registration was closed in the page, not in the handler
meta.sr.ht before 0.89.0 still accepted POST /register/step2 on instances whose operator had disabled registration: the handler returned the closed message on every error path but did not check the setting on the success path, and a CSRF token lifted from /login made the request work. Email confirmation still applied where SMTP was configured. NVD scores it 5.3 Medium on its primary CVSS 3.1 metric and fixes 0.89.0, and nothing collected shows exploitation.