CVE-2026-72584

fastschema - TOCTOU Race Condition Bypasses OTP Attempt Limit in Account Recovery

Published Aug 10, 2026 CVSS 3.1 · 7.4 High EPSS < 1% KEV · Not listed
Description
A time-of-check/time-of-use (TOCTOU) race condition in fastschema through v0.15.1 allows an unauthenticated remote attacker to bypass the OTP attempt limit on the account recovery flow, enabling brute-force attacks on 6-digit OTP codes.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
First Time appeared Fastschema
Fastschema fastschema
Vendors & Products Fastschema
Fastschema fastschema
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description A time-of-check/time-of-use (TOCTOU) race condition in fastschema through v0.15.1 allows an unauthenticated remote attacker to bypass the OTP attempt limit on the account recovery flow, enabling brute-force attacks on 6-digit OTP codes. The verifyOTPSession function in pkg/auth/local.go reads and increments the attempt counter in separate non-atomic operations, allowing concurrent requests to observe the same attempt count below the threshold and proceed past the limit check before any update is committed. A time-of-check/time-of-use (TOCTOU) race condition in fastschema through v0.15.1 allows an unauthenticated remote attacker to bypass the OTP attempt limit on the account recovery flow, enabling brute-force attacks on 6-digit OTP codes.
Type Values Removed Values Added
Description A time-of-check/time-of-use (TOCTOU) race condition in fastschema through v0.15.1 allows an unauthenticated remote attacker to bypass the OTP attempt limit on the account recovery flow, enabling brute-force attacks on 6-digit OTP codes. The verifyOTPSession function in pkg/auth/local.go reads and increments the attempt counter in separate non-atomic operations, allowing concurrent requests to observe the same attempt count below the threshold and proceed past the limit check before any update is committed.
Title fastschema - TOCTOU Race Condition Bypasses OTP Attempt Limit in Account Recovery
Weaknesses CWE-367
References
Metrics cvssV3_1

{'score': 7.4, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
TuranSec
Published
Updated
Aug 10, 2026, 1:14 PM
Reserved
Aug 10, 2026, 10:32 AM
Status
Deferred
Published
Aug 10, 2026, 11:17 AM
Modified
Oct 24, 2026, 3:10 PM