CVE-2026-110862

critical

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.

References

https://www.vulncheck.com/advisories/better-auth-1.4.0-beta.18-before-1.7.7-authentication-bypass-via-magic-link

https://github.com/better-auth/better-auth/security/advisories/GHSA-965c-763c-88jm

https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-101745

Details

Source: Mitre, NVD

Published: 2026-10-14

Updated: 2026-10-16

Risk Information

CVSS v2

Base Score: 9.4

Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:N

Severity: High

CVSS v3

Base Score: 9.1

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Severity: Critical

CVSS v4

Base 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

Severity: Critical

EPSS

EPSS: 0.00321