CVE-2025-61686
January 10, 2026
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
react-router (CDN_JS):
Affected version(s) >=7.0.0 <=7.9.3Fix Suggestion:
Update to version no_fixhttps://github.com/remix-run/react-router.git (GITHUB):
Affected version(s) >=react-router@7.0.0 <react-router@7.9.4Fix Suggestion:
Update to version react-router@7.9.4@react-router/node (NPM):
Affected version(s) >=7.0.0 <7.9.4Fix Suggestion:
Update to version 7.9.4@remix-run/node (NPM):
Affected version(s) >=0.0.0-experimental-a04f3d18 <2.17.2Fix Suggestion:
Update to version 2.17.2@remix-run/deno (NPM):
Affected version(s) >=0.0.0-experimental-a7ab46039 <2.17.2Fix Suggestion:
Update to version 2.17.2Related ResourcesĀ (3)
Do you need more information?
Contact UsCVSS v4
Base Score:
8.8
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
NONE
Vulnerable System Confidentiality
NONE
Vulnerable System Integrity
HIGH
Vulnerable System Availability
HIGH
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
9.1
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
HIGH
Availability
HIGH
Weakness Type (CWE)
Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
EPSS
Base Score:
0.03