Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to versions 8.6.64 and 9.7.0-alpha.8, an attacker who possesses a valid authentication provider token and a single MFA recovery code or SMS one-time password can create multiple authenticated sessions by sending concurrent login requests via the authData login endpoint. This defeats the single-use guarantee of MFA recovery codes and SMS one-time passwords, allowing session persistence even after the legitimate user revokes detected sessions. This issue has been patched in versions 8.6.64 and 9.7.0-alpha.8.
Published March 31, 2026.