Better AuthApplication

CVE-2026-45337

HIGH · 7.6 CVSS v3.1 Published 2026-07-15
Fix available
A fix is available. Upgrade to 1.6.11 or later.
See remediation →
80/100
Remediation priority · High
Remotely reachable 5 weeks old

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
Better Auth is an authentication and authorization library for TypeScript. From 1.6.0 until 1.6.11, the deviceAuthorization plugin treats any authenticated session as the owner of any pending device code because GET /device does not claim the row and POST /device/approve and POST /device/deny short-circuit when userId is unset, allowing an authenticated attacker who learns a valid user_code to bind the polling device to the attacker's account or deny the legitimate flow. This issue is fixed in version 1.6.11.

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 · high confidence

The deviceAuthorization plugin in Better Auth versions 1.6.0 through 1.6.11 has an authorization bypass where GET /device does not claim ownership of pending device codes, and POST /device/approve and POST /device/deny short-circuit when userId is unset. This allows any authenticated user who knows a valid user_code to bind the polling device to their own account or deny legitimate authorization flows.

MitigationUpgrade Better Auth to version 1.6.11 or later to receive the patch that properly validates device code ownership before allowing approval or denial.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

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
Better AuthApplication
Affected:>= 1.6.0, < 1.6.11

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
Low
User interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
Low

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

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check Better Auth version
    Inspect your package.json file or run `npm list better-auth` to see the installed version of better-auth
    Affected if The installed version is >= 1.6.0 and < 1.6.11
  2. Verify deviceAuthorization plugin is enabled
    Examine your auth configuration file where you initialize Better Auth - look for `deviceAuthorization` in the plugins list or imported modules
    Affected if The deviceAuthorization plugin is included in your auth setup
  3. Confirm device code endpoints are exposed
    Check your API routes configuration - the affected endpoints are GET /device, POST /device/approve, and POST /device/deny - verify these routes exist in your route definitions
    Affected if The device authorization endpoints are registered and accessible in your application
  4. Verify user authentication is in use
    Confirm that your application uses Better Auth's session-based authentication - check that users can authenticate and receive session tokens
    Affected if User authentication is enabled and users can obtain valid session credentials

You are affected if Better Auth version is between 1.6.0 and 1.6.11 inclusive, the deviceAuthorization plugin is enabled, and your users authenticate via Better Auth sessions.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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 1.6.11 or later
Fixed in 1.6.11
Interim mitigation

Upgrade Better Auth to version 1.6.11 or later to receive the patch that properly validates device code ownership before allowing approval or denial.

Recommended fix High confidence

1.6.11

  1. Upgrade Better Auth to version 1.6.11 or later to remediate the deviceAuthorization plugin vulnerability

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

Fix this in Better Auth Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing3.0 h
  • Review / QA2.0 h
9.0 hours of engineering $1,570
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,512.

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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-2026-45337 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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