Persistent account access via cross-provider OAuth checks
Published Aug 12, 2026 · Updated Aug 12, 2026
Provider confusion in affected @auth/core and NextAuth.js releases allows remote attackers to gain persistent access to victim accounts. OAuth callback checks in core/lib/oauth/checks.ts accept global state, nonce, and PKCE cookies without verifying the issuing provider. Exploitation requires multiple providers, logged-in account linking, an observable authorization request, a target callback without PKCE, and victim interaction.
Summary
What happened
Provider confusion in affected @auth/core and NextAuth.js releases allows remote attackers to gain persistent access to victim accounts. OAuth callback checks in core/lib/oauth/checks.ts accept global state, nonce, and PKCE cookies without verifying the issuing provider. Exploitation requires multiple providers, logged-in account linking, an observable authorization request, a target callback without PKCE, and victim interaction.
The record
- CVE
- CVE-2026-73419
- Published
- Aug 12, 2026
- Updated
- Aug 12, 2026
- Vendor
- Auth.js
- Product
- @auth/core
- Classifications
- CWE-346, CWE-940, CWE-345, T1098
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Aug 12, 2026CVE publishedPublication date reported by the CVE source.
- Aug 12, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 0.41.3
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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