GHSA-hjpm-7mrm-26w8
Beter Auth has an Open Redirect via Scheme-Less Callback Parameter
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Blast Radius
better-authReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects npm packages — download data is not available via public APIs for these ecosystems.
Description
Summary
The application is vulnerable to an open redirect due to improper validation of the callbackURL parameter in the email verification endpoint and any other endpoint that accepts callback url. While the server blocks fully qualified URLs (e.g., https://evil.com), it incorrectly allows scheme-less URLs (e.g., //malicious-site.com). This results in the browser interpreting the URL as https://malicious-site.com, leading to unintended redirection.
bypass for : https://github.com/better-auth/better-auth/security/advisories/GHSA-8jhw-6pjj-8723
Affected Versions
All versions prior to 1.1.19
Details
The application’s email verification endpoint (/auth/verify-email) accepts a callbackURL parameter intended to redirect users after successful email verification. While the server correctly blocks fully qualified external URLs (e.g., https://evil.com), it improperly allows scheme-less URLs (e.g., //malicious-site.com). This issue occurs because browsers interpret //malicious-site.com as https://malicious-site.com, leading to an open redirect vulnerability.
An attacker can exploit this flaw by crafting a malicious verification link and tricking users into clicking it. Upon successful email verification, the user will be automatically redirected to the attacker's website, which can be used for phishing, malware distribution, or stealing sensitive authentication tokens.
Impact
Phishing & Credential Theft – Attackers can redirect users to a fake login page, tricking them into entering sensitive credentials, which can then be stolen.
Session Hijacking & Token Theft – If used in OAuth flows, an attacker could redirect authentication tokens to their own domain, leading to account takeover.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | better-auth | all versions | 1.1.20 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for better-auth. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update better-auth to 1.1.20 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-hjpm-7mrm-26w8 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-hjpm-7mrm-26w8 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-hjpm-7mrm-26w8. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-hjpm-7mrm-26w8 in your dependencies?
O3 detects GHSA-hjpm-7mrm-26w8 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.