GHSA-mq59-m269-xvcx
Next.js: null origin can bypass Server Actions CSRF checks
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
Weekly download volume for affected packages — a proxy for how broadly this vulnerability is deployed.
nextnpmDescription
Summary
origin: null was treated as a "missing" origin during Server Action CSRF validation. As a result, requests from opaque contexts (such as sandboxed iframes) could bypass origin verification instead of being validated as cross-origin requests.
Impact
An attacker could induce a victim browser to submit Server Actions from a sandboxed context, potentially executing state-changing actions with victim credentials (CSRF).
Patches
Fixed by treating 'null' as an explicit origin value and enforcing host/origin checks unless 'null' is explicitly allowlisted in experimental.serverActions.allowedOrigins.
Workarounds
If upgrade is not immediately possible:
- Add CSRF tokens for sensitive Server Actions.
- Prefer
SameSite=Stricton sensitive auth cookies. - Do not allow
'null'inserverActions.allowedOriginsunless intentionally required and additionally protected.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | next | ≥ 16.0.1&&< 16.1.7 | 16.1.7 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for next. 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 next to 16.1.7 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-mq59-m269-xvcx 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-mq59-m269-xvcx 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-mq59-m269-xvcx. 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-mq59-m269-xvcx in your dependencies?
O3 detects GHSA-mq59-m269-xvcx across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.