CVE-2025-31691Network attack vector

Authentication bypass via ignored server status

Published Mar 31, 2025 · Updated Apr 29, 2025

Missing authorization in Drupal OAuth2 Server before 2.1.0 allows remote attackers to authenticate through a disabled server. The module authentication path fails to honor the configured status of the selected server entity, so disabling that server does not prevent authentication processing. Exploitation requires a configured server that an administrator has disabled; the resulting access is limited to resources available to the authenticated identity.

CVSS severity9.8
Critical
EPSS probability0.42%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Missing authorization in Drupal OAuth2 Server before 2.1.0 allows remote attackers to authenticate through a disabled server. The module authentication path fails to honor the configured status of the selected server entity, so disabling that server does not prevent authentication processing. Exploitation requires a configured server that an administrator has disabled; the resulting access is limited to resources available to the authenticated identity.

The record

CVE
CVE-2025-31691
Published
Mar 31, 2025
Updated
Apr 29, 2025
Vendor
OAuth.js
Product
OAuth2 Server
Classifications
CWE-862, CAPEC-87, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 31, 2025CVE publishedPublication date reported by the CVE source.
  2. Apr 29, 2025Record 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=0.0.0 <2.1.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

OAuth.js · OAuth2 Serverversion=0.0.0 <2.1.0

Published CVSS scores

9.8CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-862Missing Authorization
CAPEC-87Forceful Browsing
T1190Exploit Public-Facing Application

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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