CVE-2026-16642Public exploitNetwork attack vector

Account takeover via unrestricted OTP guessing

Published Aug 25, 2026 · Updated Aug 25, 2026

Improper restriction of OTP attempts in all Drupal Email Login OTP versions allows remote authenticated users to bypass 2FA by guessing codes. The OTP verification form accepts unlimited submissions during the code's validity window, and the module generates codes with rand() rather than a cryptographically secure generator. A target account must have module-provided 2FA enabled, and the attacker must pass the primary login step before repeated OTP guesses can complete login.

CVSS severityUnavailable
Unscored
EPSS probability0.19%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper restriction of OTP attempts in all Drupal Email Login OTP versions allows remote authenticated users to bypass 2FA by guessing codes. The OTP verification form accepts unlimited submissions during the code's validity window, and the module generates codes with rand() rather than a cryptographically secure generator. A target account must have module-provided 2FA enabled, and the attacker must pass the primary login step before repeated OTP guesses can complete login.

The record

CVE
CVE-2026-16642
Published
Aug 25, 2026
Updated
Aug 25, 2026
Vendor
OAuth.js
Product
Email Login OTP
Classifications
T1110
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 25, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 25, 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=*.*

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

OAuth.js · Email Login OTPversion=*.*

Published CVSS scores

No CVSS assessment is available in this record.

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

T1110Brute Force

Public exploit references

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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