by Kastro
Paper/Archive/CVE-2026-110864

CVE-2026-110864

better-auth better-auth — Better Auth 1.5.0-beta.12 before 1.7.7 Authentication Bypass via OAuth Proxy

EPSS 0.3%CVSS 9.1
critical.is priorityof 100
32
CVSS 9.1 (CNA)9.1 / 10 × 3027.3Not in CISA KEV+300.0EPSS percentile 21.3.213 × 204.3No public exploit+100.0SSVC exploitation: none+100.0
Description · from the CVE record

Better Auth from 1.5.0-beta.12 before 1.7.7 contains an authentication bypass vulnerability in the OAuth Proxy plugin that allows unauthenticated attackers to sign in as other users by forging encrypted profiles. When the proxy shares the global secret and cookie-stored state is used, attackers can obtain encrypted state for a fake profile with a victim's verified email to take over the account via implicit linking.

Affected

ProductAffectedFixed inSource
better-auth1.5.0-beta.12 – < 1.7.71.7.7CNA

Scores by source

VulnCheck (CNA)9.1CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
VulnCheck (CNA)7.4CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
CISA ADPSSVCExploitation: none · Automatable: no · Technical impact: total

References

advisorygithub.com/better-auth/better-auth/security/advisories/GHSA-r4xp-prcw-77qfwriteupvulncheck.com/advisories/better-auth-1.5.0-beta.12-before-1.7.7-authentication-bypass-via-oauth-proxy