CVE-2026-72584
fastschema - TOCTOU Race Condition Bypasses OTP Attempt Limit in Account Recovery
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.
INFO
Published Date :
Aug. 10, 2026, 11:17 a.m.
Last Modified :
Aug. 28, 2026, 6:51 p.m.
Remotely Exploit :
No
Source :
309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c
Affected Products
The following products are affected by CVE-2026-72584
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | HIGH | 309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c | ||||
| CVSS 3.1 | HIGH | MITRE-CVE |
Solution
- Update fastschema to version v0.15.2 or later.
- Ensure OTP attempt counters are updated atomically.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-72584.
| URL | Resource |
|---|---|
| https://github.com/fastschema/fastschema | |
| https://github.com/fastschema/fastschema/blob/main/pkg/auth/local.go |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-72584 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-72584
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-72584 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-72584 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Aug. 10, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-72584', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-08-10T13:13:37.167947Z'} -
CVE Modified by 309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c
Aug. 10, 2026
Action Type Old Value New Value Changed Affected [{'vendor': 'fastschema', 'product': 'fastschema', 'versions': [{'status': 'affected', 'version': '0', 'lessThan': '0.15.1', 'versionType': 'semver'}]}] [{'vendor': 'fastschema', 'product': 'fastschema', 'versions': [{'status': 'affected', 'version': '0', 'versionType': 'semver', 'lessThanOrEqual': '0.15.1'}], 'defaultStatus': 'unknown'}] Changed 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. -
New CVE Received by 309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c
Aug. 10, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'fastschema', 'product': 'fastschema', 'versions': [{'status': 'affected', 'version': '0', 'lessThan': '0.15.1', 'versionType': 'semver'}]}] 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. Added CVSS V3.1 AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N Added CWE CWE-367 Added Reference https://github.com/fastschema/fastschema Added Reference https://github.com/fastschema/fastschema/blob/main/pkg/auth/local.go