# CVE-2026-53516: Better Auth: Account takeover via OAuth auto-link to unverified pre-registered email

> Attackers can take over accounts by pre-registering a victim's email and exploiting OAuth auto-linking that trusts provider email verification without checking local status.

- **Severity:** High 8.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 15 Jul 2026
- **Updated:** 15 Jul 2026
- **Also known as:** GHSA-g38m-r43w-p2q7

## What is CVE-2026-53516?

CVE-2026-53516 is a high-severity authentication bypass vulnerability in better-auth, published on 15 Jul 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

Better Auth is an authentication and authorization library for TypeScript. Prior to 1.6.11, Better Auth's OAuth callback auto-link gate in handleOAuthUserInfo accepts implicit account linking when the OAuth provider asserts email_verified: true without requiring the local user row's emailVerified field to also be true, allowing an attacker who pre-registers a victim email through /sign-up/email to bind the victim's OAuth identity to the attacker's account. The same primitive affects one-tap, and emailAndPassword.requireEmailVerification: true does not mitigate the link-time verification change. This issue is fixed in version 1.6.11.

Weakness: CWE-345 (Insufficient Verification of Data Authenticity), CWE-287 (Improper Authentication)

## Which versions are affected by CVE-2026-53516?

2 open source packages ship an affected version, including better-auth. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `better-auth` | npm | All versions | 1.6.11 |
| `better-auth` | npm | All versions | 1.6.11 |

Products: Better-Auth Better Auth.

## How do I fix CVE-2026-53516?

Upgrade better-auth to 1.6.11 or later.

## Is CVE-2026-53516 being exploited?

There is no known exploitation of CVE-2026-53516 in the wild and no public exploit code.

## Other vulnerabilities in better-auth

- [CVE-2026-53512](https://insights.sbomify.com/CVE-2026-53512/): Better Auth: OAuth refresh-token replay via missing client authentication on oidc-provider and mcp plugins (critical 9.1)
- [CVE-2024-56734](https://insights.sbomify.com/CVE-2024-56734/): Better Auth has an Open Redirect Vulnerability in Verify Email Endpoint (high 7.9)
- [CVE-2026-53514](https://insights.sbomify.com/CVE-2026-53514/): Better Auth: Unauthorized invitation acceptance via unverified email match in organization plugin (high 7.7)
- [CVE-2026-45337](https://insights.sbomify.com/CVE-2026-45337/): Better Auth: Device authorization approve and deny accept any authenticated session while the user code is pending (high 7.6)
- [CVE-2025-27143](https://insights.sbomify.com/CVE-2025-27143/): Beter Auth has an Open Redirect via Scheme-Less Callback Parameter (medium 6.9)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-53516 and fix it if it is affected.

What it is: CVE-2026-53516 is a high-severity authentication bypass vulnerability in better-auth, published on 15 Jul 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-53516 in the wild and no public exploit code.

Affected packages and fixed versions:
- better-auth (npm): affected all versions; fixed in 1.6.11
- better-auth (npm): affected all versions; fixed in 1.6.11

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-53516/ (Markdown: https://insights.sbomify.com/CVE-2026-53516/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-53516
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-53516
- OSV: https://osv.dev/vulnerability/CVE-2026-53516

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-53516/
Summaries are generated and may contain mistakes; the official description above is the record.