CVE-2026-39371
HIGHCVE-2026-39371 is a high-severity (CVSS 8.1) Cross-Site Request Forgery (CSRF) vulnerability in rwsdk. O3 Security confirms whether CVE-2026-39371 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
RedwoodSDK has a CSRF vulnerability in server function dispatch via GET requests
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, a proxy for how much of the ecosystem is exposed.
rwsdknpmDescription
RedwoodSDK is a server-first React framework. From 1.0.0-beta.50 to 1.0.5, erver functions exported from "use server" files could be invoked via GET requests, bypassing their intended HTTP method. In cookie-authenticated applications, this allowed cross-site GET navigations to trigger state-changing functions, because browsers send SameSite=Lax cookies on top-level GET requests. This affected all server functions -- both serverAction() handlers and bare exported functions in "use server" files. This vulnerability is fixed in 1.0.6.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | rwsdk | ≥ 1.0.0-beta.50&&< 1.0.6 | 1.0.6 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for rwsdk. 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 rwsdk to 1.0.6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-39371 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 CVE-2026-39371 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 CVE-2026-39371. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-39371 in your dependencies?
O3 detects CVE-2026-39371 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.