Vulnerability · Published Jan 10, 2026 · Assigned by GitHub_M
CVE-2025-61686React Router has Path Traversal in File Session Storage
Critical 9.1
In plain English
A critical-severity path traversal in react-router from remix-run. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 17.3% (higher than 97% of all known vulnerabilities). Ready-made attack tooling exists: public proof-of-concept code. Fixed versions are available - upgrade the affected package.
Official description
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 & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| npm | @react-router/node | 7.9.4 | GHSA-9583-h5hc-x8cw |
| npm | @remix-run/deno | 2.17.2 | GHSA-9583-h5hc-x8cw |
| npm | @remix-run/node | 2.17.2 | GHSA-9583-h5hc-x8cw |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| remix-run | react-router | @react-router/node >= 7.0.0, < 7.9.4@remix-run/deno < 2.17.2@remix-run/node < 2.17.2 |
Weakness: CWE-22 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H
References
- https://github.com/remix-run/react-router/security/advisories/GHSA-9583-h5hc-x8cw x_refsource_CONFIRM
- https://access.redhat.com/security/cve/CVE-2025-61686 vdb-entry, x_refsource_REDHAT
- RHBZ#2428423 issue-tracking, x_refsource_REDHAT
- https://security.access.redhat.com/data/csaf/v2/vex/2025/cve-2025-61686.json x_sadp-csaf-vex