CVE-2026-41948

Executive Summary

CVE-2026-41948 is a critical path traversal vulnerability affecting Dify versions 1.14.1 and prior. The flaw resides in the Plugin Daemon’s internal REST API, where insufficient URL path sanitization allows authenticated attackers to traverse out of their authorized tenant directory. By manipulating task identifiers or filename parameters with unencoded dot sequences (e.g., ../), an attacker can access internal endpoints such as debug interfaces, potentially leaking sensitive configuration data or enabling further lateral movement. The vulnerability is particularly dangerous because Dify Cloud permits unauthenticated free self-registration, making account creation trivial for any attacker. The CVSS score of 7.7 reflects the high confidentiality impact and the ease of exploitation with low privileges and no user interaction.

Supply Chain & Package Security

Dify is a Python-based open-source LLM application platform. The vulnerability exists in the Plugin Daemon component, which is part of the core Dify distribution. No specific package manager (PyPI, npm, etc.) is directly implicated, but the risk extends to any deployment using the affected version. Organizations should audit their Dify installations and ensure the Plugin Daemon is not exposed to untrusted networks.

CVSS Breakdown & Threat Level

• Attack Vector (AV): Network (N) – Exploitable remotely.
• Attack Complexity (AC): Low (L) – No special conditions required.
• Privileges Required (PR): Low (L) – Requires authenticated user account.
• User Interaction (UI): None (N) – No victim action needed.
• Scope (S): Changed (C) – Impact extends beyond the vulnerable component.
• Confidentiality (C): High (H) – Potential access to internal debug interfaces and tenant data.
• Integrity (I): None (N) – No data modification.
• Availability (A): None (N) – No denial of service.

Threat Level: High. The combination of low privileges, network exploitability, and high confidentiality impact makes this a priority for patching.

Deep Dive & Mechanics

The vulnerability exists in the Plugin Daemon’s REST API, which handles requests forwarded from the main Dify application. The API uses URL path parameters to identify tenant-specific resources. Due to insufficient sanitization, an attacker can inject path traversal sequences (e.g., ../) into the task_id or filename parameters.

Normal Request:

GET /api/tenants/{tenant_uuid}/tasks/{task_id}

Where {task_id} is a UUID.

Malicious Request:

GET /api/tenants/{victim_tenant_uuid}/tasks/../../debug/endpoint

The server fails to normalize the path, allowing the attacker to escape the tenant directory and access internal endpoints like /debug/ or /admin/.

The attacker only needs to know the victim tenant’s UUID, which can be obtained through enumeration or social engineering. Since Dify Cloud allows free self-registration, an attacker can create an account and then attempt to traverse to other tenants.

Vulnerable vs. Patched Code

Vulnerable Code (Dify <= 1.14.1):

# plugin_daemon/api.py
@app.route('/api/tenants/<tenant_uuid>/tasks/<task_id>')
def get_task(tenant_uuid, task_id):
    # No sanitization of task_id
    file_path = f"/data/tenants/{tenant_uuid}/tasks/{task_id}"
    return read_file(file_path)

Patched Code (Hypothetical):

# plugin_daemon/api.py
import os
@app.route('/api/tenants/<tenant_uuid>/tasks/<task_id>')
def get_task(tenant_uuid, task_id):
    # Sanitize task_id to prevent path traversal
    safe_task_id = os.path.basename(task_id)
    file_path = f"/data/tenants/{tenant_uuid}/tasks/{safe_task_id}"
    # Ensure path is within tenant directory
    real_path = os.path.realpath(file_path)
    base_path = os.path.realpath(f"/data/tenants/{tenant_uuid}")
    if not real_path.startswith(base_path):
        abort(403)
    return read_file(real_path)

Exploitation & Lab Setup

Red Team (Attack Simulation)

Prerequisites:

• A Dify instance (version <= 1.14.1) with the Plugin Daemon exposed.
• An authenticated user session (can be self-registered on Dify Cloud).
• Knowledge of a victim tenant UUID (can be obtained via enumeration or leaked data).

Exploit Steps:

1. Obtain a valid session token by logging in.
2. Craft a request to traverse to the debug interface:

   curl -X GET "http://target:port/api/tenants/{victim_uuid}/tasks/../../debug/endpoint" \
        -H "Authorization: Bearer <token>"
   

3. If successful, the response will contain internal debug information.

Example Payload:

GET /api/tenants/abc123/tasks/../../../etc/passwd HTTP/1.1
Host: target
Authorization: Bearer <token>

Blue Team (Defense & Detection)

Detection:

• Monitor for requests containing ../ or ..%2f in URL paths, especially in API endpoints related to tenants.
• Alert on access to /debug/, /admin/, or other internal endpoints from authenticated users.
• Use the Sigma rule below to detect path traversal attempts.

Mitigation:

• Immediately upgrade Dify to a patched version once available.
• If patching is not possible, deploy a WAF rule to block path traversal patterns.
• Restrict network access to the Plugin Daemon to only trusted internal hosts.
• Implement strict input validation and path normalization on the server side.

Indicators of Compromise (IOCs)

• URL Patterns:
  • /api/tenants/*/tasks/../
  • /api/tenants/*/tasks/..%2f
  • /api/tenants/*/tasks/../../debug/
• Log Entries:
  • HTTP 200 responses to requests containing ../ in the path.
  • Access to /debug/ or /admin/ endpoints from non-admin users.
• Network Traffic:
  • Outbound connections from the Plugin Daemon to unexpected internal IPs (if exploited for SSRF).

Detection Engineering

YARA Rule

rule detect_dify_path_traversal {
    meta:
        description = "Detects path traversal attempts in Dify Plugin Daemon API"
        author = "Valters IT"
        date = "2026-01-01"
        reference = "CVE-2026-41948"
    strings:
        $traversal1 = "../"
        $traversal2 = "..%2f"
        $traversal3 = "..%252f"
        $debug = "/debug/"
        $admin = "/admin/"
    condition:
        any of ($traversal*) and any of ($debug, $admin)
}

Sigma Rule

title: Dify Plugin Daemon Path Traversal Attempt
id: 8a9b7c6d-5e4f-3a2b-1c0d-9e8f7a6b5c4d
status: experimental
description: Detects path traversal attempts targeting Dify Plugin Daemon API
author: Valters IT
logsource:
    category: webserver
    product: apache
    service: access_log
detection:
    selection:
        cs-uri-query|contains:
            - '../'
            - '..%2f'
            - '..%252f'
        cs-uri-stem|contains:
            - '/api/tenants/'
    condition: selection
falsepositives:
    - Legitimate use of '..' in filenames (rare)
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2026-41948 Dify Plugin Daemon Path Traversal"; flow:to_server,established; content:"/api/tenants/"; http_uri; content:"../"; http_uri; distance:0; within:10; sid:1000001; rev:1;)

Remediation & Mitigation

1. Immediate Actions:

   • Disable the Plugin Daemon if not required.
   • Restrict network access to the Plugin Daemon to only trusted internal hosts.
   • Deploy a WAF with rules to block path traversal patterns.

2. Long-term Fix:

   • Upgrade Dify to a patched version once released.
   • Implement input validation and path normalization in the Plugin Daemon.
   • Conduct a security audit of all API endpoints for similar vulnerabilities.

3. Detection:

   • Enable logging for all API requests to the Plugin Daemon.
   • Monitor logs for path traversal patterns and alert on anomalies.

4. User Awareness:

   • Inform users of Dify Cloud about the vulnerability and recommend changing tenant UUIDs if possible.

Valters IT
Senior DevSecOps & Cyber Threat Intelligence Expert