parse-server: MFA SMS one-time password accepted twice under concurrent login
Impact
A race condition in the MFA SMS one-time password (OTP) login path allows two concurrent /login requests carrying the same OTP to both succeed and both receive valid session tokens, breaking the single-use property of the OTP. The vulnerability requires the attacker to already possess the victim's password and intercept the active SMS OTP (e.g. via SIM swap, network mirror, or phishing relay) and to race the legitimate login request, so the practical attack surface is narrow.
This advisory is the same class of incomplete fix as GHSA-2299-ghjr-6vjp (TOTP recovery codes) and GHSA-w73w-g5xw-rwhf (MFA recovery in authData-only login). Those previous fixes added optimistic locking only for array-typed authData fields; SMS MFA stores the OTP as a string, so the guard skipped it.
Patches
The optimistic lock has been generalized to cover primitive (string, number, boolean) and array authData fields. The lock is implemented as a shared helper applyAuthDataOptimisticLock that adds equality predicates on the original values of changed fields to the update WHERE clause. Concurrent writers racing the same single-use token now miss the WHERE condition and surface as Invalid auth data.
Workarounds
- Disable SMS MFA and use TOTP instead (TOTP tokens are time-window validated, not stored single-use).
- Place a rate limiter on the
/loginendpoint to reduce concurrent-request burst capacity.
Resources
- GitHub security advisory: https://github.com/parse-community/parse-server/security/advisories/GHSA-jpq4-7fmq-q5fj
- Fix Parse Server 9: https://github.com/parse-community/parse-server/pull/10448
- Fix Parse Server 8: https://github.com/parse-community/parse-server/pull/10449
Affected software
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| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| npm package | parse-server | >= 9.0.0, < 9.9.0-alpha.2, < 8.6.76 | 9.9.0-alpha.2, 8.6.76 |
References
- https://github.com/parse-community/parse-server/security/advisories/GHSA-jpq4-7fmq-q5fj
- https://nvd.nist.gov/vuln/detail/CVE-2026-43930
- https://github.com/parse-community/parse-server/pull/10448
- https://github.com/parse-community/parse-server/pull/10449
- https://github.com/parse-community/parse-server
- CVSS vector
CVSS:4.0/AV:N/AC:H/AT:N/PR:H/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N- Weakness (CWE)
CWE-362- Platform
- npm
- Package
parse-server- Disclosed
- 05.05.2026
- Updated
- 11.10.2026 10:22
Sources and licenses
OSV / GitHub Advisory Database - GHSA-jpq4-7fmq-q5fj - CC BY 4.0
Vulnerability history: parse-server
All published vulnerabilities of this package (npm package), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 116
- First → latest
- 06.2019 06.2026
- Without a fix
- 0
- Exploited in attacks
- 0
Severity breakdown
- Critical 17
- High 49
- Medium 40
- Low 10
Disclosures per year
- 2019: 2
- 2020: 4
- 2021: 4
- 2022: 12
- 2023: 5
- 2024: 4
- 2025: 6
- 2026: 79
-
parse-server: MFA SMS one-time password accepted twice under concurrent login this entry
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