memos is a privacy-first, lightweight note-taking service. A CORS misconfiguration exists in memos 0.20.1 and earlier where an arbitrary origin is reflected with Access-Control-Allow-Credentials set to true. This may allow an attacking website to make a cross-origin request, allowing the attacker to read private information or make privileged changes to the system as the vulnerable user account. This vulnerability is fixed in 0.21.0.