CVE-2026-41427 json
Better Auth OAuth 2.1 Provider: Unprivileged users can register OAuth clients
published 2026-04-16 6 mo ago modified 2026-10-26 13 d ago also GHSA-xr8f-h2gw-9xh6 , EUVD-2026-25617
- cvss
- 6.5
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.2%
- EPSS 0.2% chance of exploitation in 30 days, percentile 11%
- public exploits
- 0
- none known
Summary
Better Auth is an authentication and authorization library for TypeScript. Prior to 1.6.5, the clientPrivileges option documents a create action, but the OAuth client creation endpoints did not invoke the hook before persisting new clients. Deployments that configured clientPrivileges to restrict client registration were not actually restricted — any authenticated user could reach the create endpoints and register an OAuth client with attacker-chosen redirect URIs and metadata. This vulnerability is fixed in 1.6.5.
Patch / fix
- npm @better-auth/oauth-provider 1.6.5
- better-auth better-auth/oauth-provider 1.6.5
CISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
- Assessed
- 6 mo ago
Exploit prediction
0.21% chance of exploitation in the next 30 days, higher than 11% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 4.0 | 7.1 | CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:L/SA:N |
| CNA | 4.0 | 7.1 | CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
| NVD | 3.1 | 6.5 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| npm | @better-auth/oauth-provider | >=1.4.8-beta.7, <1.6.5 >=1.7.0-beta.0, <=1.7.0-beta.1 |
1.6.5 |
Affected products
- better-auth better-auth
- better-auth oauth-provider
Classification
- Weakness
-
- CWE-863 Incorrect Authorization
References
-
github.com
/better-auth/better-auth/security/advisories/GHSA-xr8f-h2gw-9xh6
web, mitigation, vendor-advisory
-
nvd.nist.gov
/vuln/detail/CVE-2026-41427
advisory
-
github.com
/better-auth/better-auth
package
Sources
- CVE List CVE-2026-41427
- GitHub Advisory GHSA-xr8f-h2gw-9xh6
- NVD CVE-2026-41427
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