Skip to content
A detailed explainer is available in Japanese. Read the Japanese explainer
Critical 9.1

better-auth、別ユーザーでログインされる欠陥 1.7.7で修正

CVE-2026-114607 First seen on SecPulse

Summary

TypeScript向け認証ライブラリ better-auth に、特定の設定の組み合わせで、他人のメールアドレスを知っているだけで本人としてログインできてしまう欠陥が見つかりました。Magic Link、OAuthログイン、account.storeStateStrategy の database 指定をすべて使っているアプリが対象です。1.7.7 で修正されているため、該当する構成なら更新を急いでください。

AI summary

Written by an external AI model and may contain mistakes. Check the original description and references below before acting on it.

TypeScript向け認証ライブラリ better-auth に、特定の設定の組み合わせで、他人のメールアドレスを知っているだけで本人としてログインできてしまう欠陥が見つかりました。Magic Link、OAuthログイン、account.storeStateStrategy の database 指定をすべて使っているアプリが対象です。1.7.7 で修正されているため、該当する構成なら更新を急いでください。

Affected packages

EcosystemPackageAffectedFixed
better-auth better-auth — —
Original description The description as published by the source.

Better Auth is an authentication and authorization library for TypeScript. From 1.4.0-beta.18 until 1.7.7, deployments that enable Magic Link with storeToken set to plain, or with storeToken set to hashed and the global verification.storeIdentifier setting also set to hashed, enable a built-in social or Generic OAuth provider, and use account.storeStateStrategy set to database can accept an OAuth sign-in state value as a Magic Link token. These settings can cause Magic Link verification records and OAuth state to resolve to the same stored identifier, allowing an unauthenticated attacker to start OAuth sign-in for a known email address and redeem the returned state through Magic Link without controlling the mailbox or completing the provider callback. The attacker can obtain a normal session for an existing user, or create an account incorrectly marked as email verified when sign-up is enabled. This issue is fixed in version 1.7.7.

Source: CVE.org (CVE Program・cvelistV5) NVD GitHub Advisory

References

We use cookies for analytics and ad measurement. This setting applies to all Game co., Ltd. sites. Details