GHSA-hq75-xg7r-rx6c
Better Call routing bug can lead to Cache Deception
Blast Radius
better-callReal-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
Using a CDN that caches (/**/*.png, /**/*.json, /**/*.css, etc...) requests, a cache deception can emerge. This could lead to unauthorized access to user sessions and personal data when cached responses are served to other users.
Details
The vulnerability occurs in the request processing logic where path sanitization is insufficient. The library splits the path using config.basePath but doesn't properly validate the remaining path components. This allows specially crafted requests that appear to be static assets (like /api/auth/get-session/api/auth/image.png assuming config.basePath=/api/auth) to bypass typical CDN cache exclusion rules while actually returning sensitive data.
The problematic code here:
const processRequest = async (request: Request) => {
const url = new URL(request.url);
const path = config?.basePath ? url.pathname.split(config.basePath)[1] : url.pathname;
Since this library is largely coupled with better-auth, it becomes more clear why this can be dangerous with an example request:
Impact
This is a cache deception vulnerability affecting better-call users with CDN caching enabled. which can expose sensitive data.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | better-call | all versions | 1.0.12 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for better-call. 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-call to 1.0.12 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-hq75-xg7r-rx6c 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-hq75-xg7r-rx6c 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-hq75-xg7r-rx6c. 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-hq75-xg7r-rx6c in your dependencies?
O3 detects GHSA-hq75-xg7r-rx6c across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.