CVE-2025-61686 — @react-router/node
CRITICALCVE-2025-61686 is a critical-severity (CVSS 9.1) Path Traversal vulnerability in @react-router/node. EPSS puts its 30-day exploitation probability at 17.3% (97th percentile). A fix is available for @react-router/node — see the affected versions and patch details below.
React Router has Path Traversal in File Session Storage
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- 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-2025-61686.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
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-router/nodenpm@remix-run/nodenpm@remix-run/denonpmDescription
React Router is a router for React. In @react-router/node versions 7.0.0 through 7.9.3, @remix-run/deno prior to version 2.17.2, and @remix-run/node prior to version 2.17.2, if createFileSessionStorage() is being used from @react-router/node (or @remix-run/node/@remix-run/deno in Remix v2) with an unsigned cookie, it is possible for an attacker to cause the session to try to read/write from a location outside the specified session file directory. The success of the attack would depend on the permissions of the web server process to access those files. Read files cannot be returned directly to the attacker. Session file reads would only succeed if the file matched the expected session file format. If the file matched the session file format, the data would be populated into the server side session but not directly returned to the attacker unless the application logic returned specific session information. This issue has been patched in @react-router/node version 7.9.4, @remix-run/deno version 2.17.2, and @remix-run/node version 2.17.2.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | @react-router/node | ≥ 7.0.0&&< 7.9.4 | 7.9.4npm install @react-router/node@7.9.4 |
| 📦npm | @remix-run/node | all versions | 2.17.2npm install @remix-run/node@2.17.2 |
| 📦npm | @remix-run/deno | all versions | 2.17.2npm install @remix-run/deno@2.17.2 |
Affected Products
react-router\/nodeshopifyremix-run\/denoshopifyremix-run\/nodeshopifyDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @react-router/node, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update @react-router/node to 7.9.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-61686 is resolved across your whole dependency graph.
Workarounds
Resolve every user-supplied path to its canonical form and reject anything that escapes the intended directory, and run the component under an account that has no read or write access outside the directory it legitimately serves.
Frequently Asked Questions
Is CVE-2025-61686 in your dependencies?
Find it across npm, including transitive dependencies.