NextAuth.js: OAuth state, nonce, and PKCE check cookies are not bound to the provider that created them

Summary

NextAuth.js provides authentication for Next.js. Prior to@auth/core 0.41.3 and next-auth 4.24.15 and 5.0.0-beta.32, Auth.js stores the OAuth/OIDC anti-CSRF checks state, nonce, and the PKCE verifier in global cookies that are not bound to the provider that created them. On callback, a check value minted during a sign-in started with one provider can satisfy the callback for a different provider because the stored cookie is not verified against the callback provider's identity, including the provider ID, issuer, client ID, or redirect URI. In a multi-provider application that permits account linking while logged in, when one provider's authorization request is observable and a target provider callback can be satisfied without a PKCE verifier, an attacker can lure a victim into starting a legitimate same-origin flow and link the attacker's target-provider account to the victim's Auth.js user. The linked provider grants the attacker persistent sign-in to the victim's account, while cross-site request forgery alone is insufficient. This issue is fixed in @auth/core 0.41.3 and next-auth 4.24.15 and 5.0.0-beta.32.

Timeline

1. Aug 12, 2026, 8:23 PM UTCCVE published
2. Aug 13, 2026, 3:32 PM UTCCISA SSVC assessment

   Exploitation: none · Automatable: no · Technical impact: total

3. Aug 13, 2026, 3:32 PM UTCRecord last updated

Affected versions

• nextauthjs next-auth

  fixed in 4.24.15; From 5.0.0-beta.4 · fixed in 5.0.0-beta.32

• @auth core

  fixed in 0.41.3

• @auth/corenpm

  fixed in 0.41.3

• next-authnpm

  From 5.0.0-beta.1 · fixed in 5.0.0-beta.32

• next-authnpm

  fixed in 4.24.15

References 7