CVE-2026-33624
EPSS 0.03%Parse Server: MFA recovery code single-use bypass via concurrent requests
Published: 3/24/2026Modified: 3/27/2026
Description
### Impact 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. ### Patches The login handler now uses optimistic locking when updating auth data that contains consumed single-use tokens. If a concurrent request has already modified the recovery array, the update fails and the login is rejected. ### Workarounds There are no known workarounds.
Affected packages (2)
- Bitnami/parsefrom 0, < 8.6.60, >= 9.0.0, < 9.6.0
- npm/parse-server>= 9.0.0, < 9.6.0-alpha.54
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 4.0 | — | 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 |
References (7)
- ADVISORYhttps://nvd.nist.gov/vuln/detail/CVE-2026-33624
- PATCHhttps://github.com/parse-community/parse-server
- WEBhttps://github.com/parse-community/parse-server/commit/5e70094250a36bfcc14ecd49592be2b94fba66ff
- WEBhttps://github.com/parse-community/parse-server/commit/fc3da35a81d5083b453e8967cabcc880f1a3bd0c
- WEBhttps://github.com/parse-community/parse-server/pull/10275
- WEBhttps://github.com/parse-community/parse-server/pull/10276
- WEBhttps://github.com/parse-community/parse-server/security/advisories/GHSA-2299-ghjr-6vjp