Race condition in parse-server - CVE-2026-43930
Published: May 23, 2026
parse-server
Detailed vulnerability description
The vulnerability allows a remote user to obtain a valid session token by reusing a single-use sms one-time password.
The vulnerability exists due to a race condition in the mfa sms one-time password login path when processing concurrent /login requests carrying the same otp. A remote user can send a concurrent login request with the same intercepted otp to obtain a valid session token by reusing a single-use sms one-time password.
Exploitation requires possession of the victim's password, interception of the active sms otp, and racing the legitimate login request.