better-auth SCIM 1.4.0-beta.27 through 1.6.21 Account Takeover via Provider-ID Collision
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Attack requirements
- None
- Impact type
- —
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- No fix listed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA.
Summary
@better-auth/scim (a better-auth plugin) versions >= 1.4.0-beta.27 through <= 1.6.21 and >= 1.7.0-beta.0 through <= 1.7.0-beta.9 contain an authorization bypass. SCIM token issuance did not reject provider IDs already used by existing SSO, SAML, OIDC, generic OAuth, or social account providers, and the same logical provider ID was used for both SCIM provider configuration and account ownership. An authenticated user could mint a SCIM token whose provider ID collided with an existing provider namespace, causing SCIM user routes to resolve account rows the token never provisioned. This allowed listing, reading, updating (including rewriting global profile/email fields without uniqueness checks), and deleting global user accounts and sessions, resulting in account takeover and unauthorized deprovisioning. Fixed in 1.6.22 and 1.7.0-beta.10 (1.7.0-rc.0).
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| better-auth | scim | 1.4.0-beta.27 and later | — | No fix listed | CNA |
| better-auth | scim | 1.7.0-beta.0 and later | — | No fix listed | CNA |
- scim Vendorbetter-auth Affected 1.4.0-beta.27 and later Fixed in — No fix listed CNA
- scim Vendorbetter-auth Affected 1.7.0-beta.0 and later Fixed in — No fix listed CNA
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2026-67330
- 2026-10-03 Alias added: GHSA-6mwf-73fj-3358
References
More better-auth vulnerabilities
- TI-2025-38277 Better Auth: Unauthenticated API key creation through api-key plugin CVSS 4.0CRITICAL 9.3
- TI-2026-47627 better-auth SCIM 1.5.0 before 1.7.0-beta.4 Authorization Bypass CVSS 4.0HIGH 8.7
- TI-2025-20000 Beter Auth has an Open Redirect via Scheme-Less Callback Parameter CVSS 4.0MEDIUM 6.9
- TI-2026-13066 better-auth better-icons scan_project_icons/sync_icon path traversal CVSS 4.0MEDIUM 4.8
- TI-2026-79320 OAuth state accepted as Magic Link token in Better Auth CVSS 3.1CRITICAL 9.1
- TI-2026-74552 Authentication bypass in Better Auth Magic Link verification CVSS 4.0CRITICAL 9.3
Sources
- CVE-2026-67330 · CVE Program
- CVE-2026-67330 · NVD
- FIRST EPSS
- GHSA-6mwf-73fj-3358 · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences