CVE-2026-33624
Parse Server: MFA recovery code single-use bypass via concurrent requests
- State
- Published
- Severity
- 2.1 Low
- Published
- Mar 24, 2026
- Updated
- Mar 25, 2026
- Reserved
- Mar 23, 2026
Description
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 2.1 Low | 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 | GitHub_M |
Weaknesses
- CWE-367 Time-of-check Time-of-use (TOCTOU) Race Condition
Affected Products
| Product | Versions |
|---|---|
parse-serverparse-community |
|
References
- https://github.com/parse-community/parse-server/security/advisories/GHSA-2299-ghjr-6vjp
- https://github.com/parse-community/parse-server/pull/10275
- https://github.com/parse-community/parse-server/pull/10276
- https://github.com/parse-community/parse-server/commit/5e70094250a36bfcc14ecd49592be2b94fba66ff
- https://github.com/parse-community/parse-server/commit/fc3da35a81d5083b453e8967cabcc880f1a3bd0c
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