Is this vulnerability remotely exploitable?

Yes. An attacker only needs network access to the vulnerable HTTP endpoints and the ability to control or modify the session cookie value; no local access to the server filesystem is required.

Does exploitation require authentication?

Not necessarily. If anonymous users receive session cookies (a common pattern), an unauthenticated attacker can manipulate those cookies. If sessions are only issued post-login, then access to a valid session cookie is required, but the attack still occurs over standard HTTP requests.

What is the safest general fix pattern?

Use signed (or encrypted) cookies for session identifiers and ensure the session file implementation strictly confines all file operations to a dedicated session directory. Paths derived from identifiers should be normalized and validated so that traversal outside this directory is impossible, and identifiers themselves should be opaque tokens rather than user-controlled path fragments.

Severity:

CRITICAL RISK

(9.1)

Path Traversal in File-Based Session Storage (CWE-22) for React Router and Remix Node/Deno

CVE-2025-61686

Published:

Jan 9, 2026

Status:

Analyzed

Summary

Affected Context

Exploit Preconditions

Why This Happens

Potential Impact

General Mitigation Guidance

How Teams Detect Issues Like This

Frequently Asked Questions

Source

NDV

Recent Vulnerabilities

CWE-77;CWE-78

HIGH RISK

HIGH

(7.3)

OS Command Injection (CWE-78) in Totolink A7100RU setGameSpeedCfg CGI Handler

Remote Code Execution on the Router

April 6, 2026

CWE-77;CWE-78

HIGH RISK

HIGH

(7.3)

OS Command Injection (CWE-78) in Totolink A7100RU setFirewallType Handler

Remote Code Execution on Router Firmware

April 6, 2026

Vulnerability Type

Category:

Path Traversal / Directory Traversal

CWE:

CWE-22

Impact:

Arbitrary File Read/Write via Session Storage Path Traversal (constrained by format and filesystem permissions)

Severity:

CRITICAL RISK

(9.1)

CVSS Version:

3.1

Vulnerability Type

Category:

Path Traversal / Directory Traversal

CWE:

CWE-22

Impact:

Arbitrary File Read/Write via Session Storage Path Traversal (constrained by format and filesystem permissions)

Severity:

CRITICAL RISK

(9.1)

CVSS Version:

3.1

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Ask AI for summary of CodeAnt

Path Traversal in File-Based Session Storage (CWE-22) for React Router and Remix Node/Deno

Summary

Affected Context

Exploit Preconditions

Why This Happens

Potential Impact

General Mitigation Guidance

How Teams Detect Issues Like This

Frequently Asked Questions

Source

Recent Vulnerabilities

HIGH RISK

HIGH

(7.3)

OS Command Injection (CWE-78) in Totolink A7100RU setGameSpeedCfg CGI Handler

HIGH RISK

HIGH

(7.3)

OS Command Injection (CWE-78) in Totolink A7100RU setFirewallType Handler

Vulnerability Type

Vulnerability Type

Vulnerability Type

Catch This CVE While Code Is Being Written

Ship clean & secure code faster

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