---
id: CVE-2026-80192
title: >-
  @better-auth/sso before 1.6.27 (and before 1.4.8 in the 1.4.x line and before
  1.7.0-rc.5 in the 1.7 prerelease line) contains two domain-ownership flaws
summary: >-
  @better-auth/sso before 1.6.27 (and before 1.4.8 in the 1.4.x line and before
  1.7.0-rc.5 in the 1.7 prerelease line) contains two domain-ownership flaws.
  When domain verification is disabled, automatic organization assignment
  accepts unv…
severity: high
cvss: 8.1
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N'
cwe:
  - CWE-287
published: '2026-08-26'
updated: '2026-09-24'
sourceUpdated: '2026-09-24T20:43:32.537'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-80192'
references:
  - url: >-
      https://github.com/better-auth/better-auth/security/advisories/GHSA-8c5h-wx78-2cfg
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/better-auth-sso-before-1.6.27-domain-ownership-authentication-bypass
    label: disclosure@vulncheck.com
tags:
  - nvd
epss: 0.00363
epssPercentile: 0.2749
ingestedAt: '2026-08-29T21:42:34.068Z'
---

## Overview

@better-auth/sso before 1.6.27 (and before 1.4.8 in the 1.4.x line and before 1.7.0-rc.5 in the 1.7 prerelease line) contains two domain-ownership flaws. When domain verification is disabled, automatic organization assignment accepts unverified provider domains, allowing an authenticated organization owner/administrator to register an SSO provider for an arbitrary domain and have users with matching email domains added to the attacker's organization with default member permissions. When domain verification is enabled, a race condition between the verify-domain and update-provider endpoints can apply completed DNS proof to a different domain; combined with implicit account linking, this can link an attacker-controlled identity provider to an existing user account. Exploitation requires the SSO plugin (and, for the org-assignment path, the organization plugin) with the relevant configuration enabled.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.