Better Auth Open Redirect Vulnerability in originCheck Middleware Affects Multiple Routes
Summary
An open redirect has been found in the originCheck middleware function, which affects the following routes: /verify-email, /reset-password/:token, /delete-user/callback, /magic-link/verify, /oauth-proxy-callback.
Details
In the matchesPattern function, url.startsWith( can be deceived with a url that starts with one of the trustedOrigins.
const matchesPattern = (url: string, pattern: string): boolean => {
if (url.startsWith("/")) {
return false;
}
if (pattern.includes("*")) {
return wildcardMatch(pattern)(getHost(url));
}
return url.startsWith(pattern);
};Open Redirect PoCs
export const auth = betterAuth({
baseURL: 'http://localhost:3000',
trustedOrigins: [
"http://trusted.com"
],
emailAndPassword: {
...
},
})/reset-password/:token
<img width="481" alt="image" src="https://github.com/user-attachments/assets/46e7871a-1dad-4375-af94-0446e29aaab6" />
<br/>
<img width="518" alt="image 1" src="https://github.com/user-attachments/assets/83abfb53-6fc9-4d1f-918d-9b4ce093c808" />
/verify-email
<img width="549" alt="image" src="https://github.com/user-attachments/assets/7dd424b7-42a4-4616-aa73-fcc2e3eeb309" />
<br/>
<img width="436" alt="image" src="https://github.com/user-attachments/assets/54f11636-0a3e-4e83-9a09-57c5e8ba98cd" />
/delete-user/callback
<img width="545" alt="image" src="https://github.com/user-attachments/assets/2ff1b217-d069-48fb-81c1-f8c8792d34a4" />
<br/>
<img width="492" alt="image" src="https://github.com/user-attachments/assets/71df11db-9d38-4f34-abe1-add9d60b3486" />
/magic-link/verify
<img width="379" alt="image" src="https://github.com/user-attachments/assets/6b6b6a8a-59b6-4a65-9df3-57d5b2f6eb0f" />
<br/>
<img width="413" alt="image" src="https://github.com/user-attachments/assets/82a5c9c6-2ea0-44eb-af48-40732657b59e" />
/oauth-proxy-callback
<img width="548" alt="image" src="https://github.com/user-attachments/assets/d8d2ee51-e9fd-4337-bec3-a70afd1ceacb" />
<br/>
<img width="544" alt="image" src="https://github.com/user-attachments/assets/f097d406-b965-4f85-b124-9b0ef1cc2689" />
Impact
Untrusted open redirects in various routes.
Affected software
Click a technology to see all vulnerabilities affecting it.
| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| npm package | better-auth | < 1.2.10 | 1.2.10 |
References
- CVSS vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X- Weakness (CWE)
CWE-601- Platform
- npm
- Package
better-auth- Disclosed
- 07.07.2025
- Updated
- 11.10.2026 10:22
Sources and licenses
OSV / GitHub Advisory Database - GHSA-36rg-gfq2-3h56 - CC BY 4.0
Vulnerability history: better-auth
All published vulnerabilities of this package (npm package), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 22
- First → latest
- 12.2024 07.2026
- Without a fix
- 0
- Exploited in attacks
- 0
Severity breakdown
- Critical 2
- High 14
- Medium 3
- Low 3
Disclosures per year
- 2024: 1
- 2025: 8
- 2026: 13
-
Better Auth Open Redirect Vulnerability in originCheck Middleware Affects Multiple Routes this entry
Know which vulnerabilities affect your application
With the DockRay integration and software inventory enabled, DockRay checks reported component versions against known vulnerabilities and notifies you about confirmed matches. Coverage depends on the supported technology and available advisory data.