CVE-2026-33624CWE-367

Parse Server: MFA recovery code single-use bypass via concurrent requests

Low · published March 24, 2026

CVSS v4.0
2.1
EPSS
0%
Percentile
21.7
In the wild
Unconfirmed
What it is

Parse Server is an open source backend that can be deployed to any infrastructure that can run Node.js. Prior to versions 8.6.60 and 9.6.0-alpha.54, an attacker who obtains a user's password and a single MFA recovery code can reuse that recovery code an unlimited number of times by sending concurrent login requests. This defeats the single-use design of recovery codes. The attack requires the user's password, a valid recovery code, and the ability to send concurrent requests within milliseconds. This issue has been patched in versions 8.6.60 and 9.6.0-alpha.54.

The record
Technical detail
CVSS v4.0
2.1 · LOW
Vector
CVSS:4.0/AV:N/AC:H/AT:P/PR:H/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N
EPSS
0.00302 · 21.7th percentile
Weakness
CWE-367 · Time-of-check Time-of-use (TOCTOU) Race Condition
Published
2026-03-24T18:28Z
EPSS history
Timeline
  • 24 MAR 18:28Z
    Parse Server: MFA recovery code single-use bypass via concurrent requests
    cvelistv5