CVE-2026-41427Network attack vector

Unauthorized OAuth client registration via skipped privilege hook

Published Apr 24, 2026 · Updated Apr 24, 2026

Incorrect authorization in Better Auth OAuth Provider allows remote authenticated users to register unauthorized OAuth clients. The /oauth2/create-client and /admin/oauth2/create-client handlers persisted attacker-supplied redirect URIs and metadata without calling clientPrivileges with the create action. Exploitation requires clientPrivileges restrictions and reachable creation endpoints; the resulting clients can support deceptive first-party phishing flows.

CVSS severity7.1
High
EPSS probability0.21%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Incorrect authorization in Better Auth OAuth Provider allows remote authenticated users to register unauthorized OAuth clients. The /oauth2/create-client and /admin/oauth2/create-client handlers persisted attacker-supplied redirect URIs and metadata without calling clientPrivileges with the create action. Exploitation requires clientPrivileges restrictions and reachable creation endpoints; the resulting clients can support deceptive first-party phishing flows.

The record

CVE
CVE-2026-41427
Published
Apr 24, 2026
Updated
Apr 24, 2026
Vendor
Better Auth
Product
Better Auth OAuth Provider Plugin
Classifications
CWE-863
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 24, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 24, 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=>= 1.4.8-beta.7, < 1.6.5
  2. Affected versionversion=>= 1.7.0-beta.0, <= 1.7.0-beta.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Better Auth · Better Auth OAuth Provider Pluginversion=>= 1.4.8-beta.7, < 1.6.5; version=>= 1.7.0-beta.0, <= 1.7.0-beta.1
Better Auth · Better Authversion=>= 1.4.8-beta.7, < 1.6.5; version=>= 1.7.0-beta.0, <= 1.7.0-beta.1

Published CVSS scores

7.1Better AuthCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:L/SA: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.

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 exploitUnconfirmed

Weakness, pattern, technique

CWE-863Incorrect Authorization

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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