CVE-2026-72584Network attack vector

Account takeover via non-atomic OTP attempt updates

Published Aug 10, 2026 · Updated Aug 10, 2026

TOCTOU in FastSchema 0.15.1 and earlier allows remote attackers to bypass recovery OTP limits and reset account passwords. The verifyOTPSession function reads the attempt count and later writes an incremented value, so concurrent guesses can reuse the same below-limit count. OTP-based account recovery must be enabled; unauthenticated attackers can request a recovery session and brute-force its six-digit code.

CVSS severity7.4
High
EPSS probability0.25%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

TOCTOU in FastSchema 0.15.1 and earlier allows remote attackers to bypass recovery OTP limits and reset account passwords. The verifyOTPSession function reads the attempt count and later writes an incremented value, so concurrent guesses can reuse the same below-limit count. OTP-based account recovery must be enabled; unauthenticated attackers can request a recovery session and brute-force its six-digit code.

The record

CVE
CVE-2026-72584
Published
Aug 10, 2026
Updated
Aug 10, 2026
Vendor
FastSchema
Product
FastSchema
Classifications
CWE-367, T1110
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 10, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 10, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <=0.15.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

FastSchema · FastSchemaversion=0 <=0.15.1

Published CVSS scores

7.4TuranSecCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-367Time-of-check Time-of-use (TOCTOU) Race Condition
T1110Brute Force

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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