{"id":"CVE-2026-53516","aliases":["GHSA-g38m-r43w-p2q7"],"url":"https://o3.security/vulnerability/CVE-2026-53516","summary":"Better Auth: Account takeover via OAuth auto-link to unverified pre-registered email","details":"Better Auth is an authentication and authorization library for TypeScript. Prior to 1.6.11, Better Auth's OAuth callback auto-link gate in handleOAuthUserInfo accepts implicit account linking when the OAuth provider asserts email_verified: true without requiring the local user row's emailVerified field to also be true, allowing an attacker who pre-registers a victim email through /sign-up/email to bind the victim's OAuth identity to the attacker's account. The same primitive affects one-tap, and emailAndPassword.requireEmailVerification: true does not mitigate the link-time verification change. This issue is fixed in version 1.6.11.","published":"2026-07-15T17:13:16.431Z","modified":"2026-08-12T03:51:12.160703771Z","cvss":{"score":8.3,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:L"},"epss":{"score":0.00232,"percentile":0.13894,"asOf":"2026-08-30"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"npm","name":"better-auth","fixedVersion":"1.6.11"}],"fix":{"url":"https://github.com/better-auth/better-auth/commit/da7e50beee849c59a2ed1ec6b3a38cc6ab9fb563","label":"better-auth/better-auth@da7e50b"},"references":[{"type":"WEB","url":"https://github.com/better-auth/better-auth/releases/tag/v1.6.11"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53516.json"},{"type":"ADVISORY","url":"https://github.com/better-auth/better-auth/security/advisories/GHSA-g38m-r43w-p2q7"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-53516"},{"type":"FIX","url":"https://github.com/better-auth/better-auth/commit/da7e50beee849c59a2ed1ec6b3a38cc6ab9fb563"},{"type":"FIX","url":"https://github.com/better-auth/better-auth/pull/9578"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:12.160703771Z"}}