Better Auth from 1.4.0-beta.18 before 1.7.7 contains an authentication bypass vulnerability that allows unauthenticated attackers to sign in as other users by reusing OAuth state values as Magic Link tokens. Attackers can start an OAuth sign-in with a victim's email and submit the returned state to Magic Link verification, gaining sessions or creating falsely email-verified accounts.
Advisories

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Fixes

Solution

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Workaround

No workaround given by the vendor.

History

Thu, 15 Oct 2026 14:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}


Wed, 14 Oct 2026 23:00:00 +0000

Type Values Removed Values Added
Description Better Auth from 1.4.0-beta.18 before 1.7.7 contains an authentication bypass vulnerability that allows unauthenticated attackers to sign in as other users by reusing OAuth state values as Magic Link tokens. Attackers can start an OAuth sign-in with a victim's email and submit the returned state to Magic Link verification, gaining sessions or creating falsely email-verified accounts.
Title Better Auth 1.4.0-beta.18 before 1.7.7 Authentication Bypass via Magic Link
First Time appeared Better-auth
Better-auth better Auth
Weaknesses CWE-287
CPEs cpe:2.3:a:better-auth:better_auth:*:*:*:*:*:*:*:*
Vendors & Products Better-auth
Better-auth better Auth
References
Metrics cvssV3_1

{'score': 9.1, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N'}

cvssV4_0

{'score': 9.3, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-10-15T13:34:05.213Z

Reserved: 2026-10-14T22:18:33.239Z

Link: CVE-2026-110862

cve-icon Vulnrichment

Updated: 2026-10-15T13:33:58.477Z

cve-icon NVD

Status : Deferred

Published: 2026-10-14T23:17:27.673

Modified: 2026-10-16T18:25:45.343

Link: CVE-2026-110862

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-10-17T12:45:08Z

Weaknesses