CVE-2026-33245 — react-router
HIGHCVE-2026-33245 is a high-severity (CVSS 8) Cross-site Scripting (XSS) vulnerability in react-router. A fix is available for react-router — see the affected versions and patch details below.
React Router vulnerable to XSS in unstable RSC redirect handling via javascript: redirect targets
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-2026-33245.
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-2026-33245 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 379,842 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-routernpmDescription
React Router is a router for React. In versions 7.7.0 through 7.13.1, when using React Router's unstable React Server Components (RSC) APIs, there is a potential client-side Cross-Site Scripting (XSS) vulnerability in the RSC redirect handling if redirects come from untrusted sources. This does not impact applications that are not using the unstable RSC APIs in React Router. This is patched in version 7.13.2.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | react-router | ≥ 7.7.0&&< 7.13.2 | 7.13.2npm install react-router@7.13.2 |
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 7.13.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-33245 is resolved across your whole dependency graph.
Workarounds
Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-33245 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2026-33245. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
To mitigate this Cross-Site Scripting (XSS) vulnerability, ensure that applications utilizing React Router's unstable React Server Components (RSC) APIs only process redirects from trusted sources. Avoiding the use of these unstable APIs in production environments where untrusted redirect sources cannot be guaranteed is also recommended.Source: Red Hat security advisory for CVE-2026-33245 (CC BY 4.0)
| Product | Fixed in | Advisory |
|---|---|---|
| Red Hat Data Grid 8.6.2 | react-router | RHSA-2026:41951 |
| Red Hat OpenShift AI 3.3 | rhoai/odh-dashboard-rhel9:1783082634 | RHSA-2026:37275 |
| Red Hat OpenShift AI 3.4 | rhoai/odh-mod-arch-automl-rhel9:1782722421 | RHSA-2026:34456 |
| Red Hat OpenShift AI 3.4 | rhoai/odh-dashboard-rhel9:1787347991 | RHSA-2026:60520 |
| Red Hat OpenShift Dev Spaces 3.29 | devspaces/dashboard-rhel9:1784737150 | RHSA-2026:48124 |
Frequently Asked Questions
Is CVE-2026-33245 in your dependencies?
O3 Security finds CVE-2026-33245 across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.