GitHub Advisoryadvisory · npm

GHSA-9583-h5hc-x8cw React Router has Path Traversal in File Session Storage

CRITICAL Published 2026-01-08 Modified 2026-09-18 Official page ↗
Aliases
CVE-2025-61686
Ecosystem
npm
Packages
@react-router/node, @remix-run/node, @remix-run/deno
Severity
Critical
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H
Weaknesses
CWE-22
Reviewed
2026-01-08

Affected packages

• npm @react-router/node: >= 7.0.0, < 7.9.4 → fixed in 7.9.4 • npm @remix-run/node: < 2.17.2 → fixed in 2.17.2 • npm @remix-run/deno: < 2.17.2 → fixed in 2.17.2

Description

If applications use `createFileSessionStorage()` 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.

Related

Alias · CVE (1)

Weakness · CWE (1)

  • CWE-22 Improper Limitation of a Pathname to a Restricted Directory weakness

References