Next AuthApplication · Nextauth.js

CVE-2022-35924

CRITICAL · 9.1 CVSS v3.1 Published 2022-08-02
Fix available
A fix is available. Upgrade to 3.29.10 / 4.10.3 or later.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click Patch available

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
NextAuth.js is a complete open source authentication solution for Next.js applications. `next-auth` users who are using the `EmailProvider` either in versions before `4.10.3` or `3.29.10` are affected. If an attacker could forge a request that sent a comma-separated list of emails (eg.: `[email protected],[email protected]`) to the sign-in endpoint, NextAuth.js would send emails to both the attacker and the victim's e-mail addresses. The attacker could then login as a newly created user with the email being `[email protected],[email protected]`. This means that basic authorization like `email.endsWith("@victim.com")` in the `signIn` callback would fail to communicate a threat to the developer and would let the attacker bypass authorization, even with an `@attacker.com` address. This vulnerability has been patched in `v4.10.3` and `v3.29.10` by normalizing the email value that is sent to the sign-in endpoint before accessing it anywhere else. We also added a `normalizeIdentifier` callback on the `EmailProvider` configuration, where you can further tweak your requirements for what your system considers a valid e-mail address. (E.g.: strict RFC2821 compliance). Users are advised to upgrade. There are no known workarounds for this vulnerability. If for some reason you cannot upgrade, you can normalize the incoming request using Advanced Initialization.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis
How this class of weakness works · CWE-20

The application accepts input without confirming it is well-formed or within expected bounds, so malformed data can push the program into states its author never anticipated. Attackers probe these gaps to trigger crashes, bypass logic, or feed tainted values into more dangerous operations downstream. Remediating it well means validating and normalising every input at the boundary against a strict allow-list — not merely filtering known-bad values.

General guidance for the improper input validation class — the official description and references above are authoritative for this specific CVE. Want a bespoke review and a reviewed fix? Ask our team →

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Next AuthApplication
Affected:< 3.29.10>= 4.0.0, < 4.10.3

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 3.29.10 / 4.10.3 or later
Fixed in 3.29.104.10.3
Vendor patch github.com →
Recommended fix High confidence

next-auth v4.10.3 (for v4.x users) or next-auth v3.29.10 (for v3.x users)

  1. Identify your current NextAuth.js version by checking package.json
  2. For NextAuth.js v4.x users: Run `npm install [email protected]` or `yarn add [email protected]` or `pnpm add [email protected]` to upgrade to the patched version
  3. For NextAuth.js v3.x users: Run `npm install [email protected]` to upgrade to the patched v3 release
  4. After upgrading, verify the EmailProvider configuration still works as expected
  5. Optionally, configure the new `normalizeIdentifier` callback on EmailProvider to add custom email validation (e.g., RFC2821 compliance)
Caveat The email normalization may reject previously accepted malformed email addresses; review any custom email validation logic

Generated from the published advisory — verify against the referenced sources before acting.

We can perform the upgrade in your staging environment and verify nothing breaks — typical engagement from $2,300. Get the upgrade done

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2022-35924 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
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