CVE-2026-53663 — react-router
LOWCVE-2026-53663 is a low-severity (CVSS 3.1) Cross-Site Request Forgery (CSRF) vulnerability in react-router. A fix is available for react-router — see the affected versions and patch details below.
React Router: `handleDocumentRequest` CSRF check covers `POST` only; PUT/PATCH/DELETE bypass
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-53663.
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.
How urgent is this, really
CVE-2026-53663 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 376,715 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
react-routernpm@remix-run/server-runtimenpmDescription
React Router is a router for React. From 7.12.0 until 7.15.1, certain CSRF checks in React Router v7 Framework Mode were insufficient and run on POST requests, but were bypassed on PUT/PATCH/DELETE requests. This is a low severity vulnerability because modern browser protections (CORS preflight, SameSite cookies) already block the cross-origin attack vectors that this missing CSRF check would otherwise gate. This vulnerability is fixed in 7.15.1.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | react-router | ≥ 7.12.0&&< 7.15.1 | 7.15.1npm install react-router@7.15.1 |
| 📦npm | @remix-run/server-runtime | ≥ 2.17.3&&< 2.17.5 | 2.17.5npm install @remix-run/server-runtime@2.17.5 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for react-router, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update react-router to 7.15.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-53663 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 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-53663 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2026-53663. 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-2026-53663 in your dependencies?
O3 Security finds CVE-2026-53663 across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.