CVE-2026-102103 — Kiteworks Email Protection Gateway before version 9.5.0 is vulnerable to Server-Side…¶

Key facts

CVE-2026-102103 is a Critical (9.1) vulnerability: Kiteworks Email Protection Gateway before version 9.5.0 is vulnerable to Server-Side…. This entry ships a detection-only PoC and a Docker test lab.


CVE	CVE-2026-102103
Severity	Critical (9.1)
Detection / prevention	—
PoC	poc.py
Source	2026/CVE-2026-102103/

Details¶

English | 한국어

Description¶

Kiteworks Email Protection Gateway before version 9.5.0 is vulnerable to Server-Side Request Forgery (SSRF). A server-side request forgery (SSRF) weakness in Kiteworks Email Protection Gateway could allow a remote, unauthenticated attacker to induce the gateway to issue crafted requests to internal or otherwise unintended network destinations. The requests are triggered while the gateway retrieves a certificate revocation list in an inbound message. Depending on the services reachable from the gateway, this could disclose sensitive internal information or disrupt gateway operation.

Vulnerability Details¶

Property	Value
CVE ID	CVE-2026-102103
Type	SSRF
CVSS Score	9.1

Proof of Concept¶

Download¶

# Download PoC script
curl -O https://raw.githubusercontent.com/fankh/vulnerability-poc/main/2026/CVE-2026-102103/poc.py

Usage¶

# Run PoC against target
python3 poc.py --target <TARGET_URL>

# With authentication
python3 poc.py --target <TARGET_URL> --username <USER> --password <PASS>

⚠️ Warning: This PoC is for authorized security testing only. It uses detection-only techniques and does not exploit or damage target systems.

Test Lab¶

This repository includes a Docker-based test environment with both vulnerable and patched applications.

Quick Start¶

# Clone and navigate to CVE directory
cd CVE-2026-102103

# Start both applications
docker-compose up -d

# Run tests
./run-tests.sh    # Linux/Mac
./run-tests.ps1   # Windows PowerShell

Application Endpoints¶

Application	URL	Status
Vulnerable App	http://localhost:8080	Shows vulnerability
Patched App	http://localhost:8081	Demonstrates fix

Directory Structure¶

├── README.md           # English documentation
├── README_KO.md        # Korean documentation
├── poc.py              # PoC detection script
├── docker-compose.yml  # Container orchestration
├── run-tests.sh        # Linux/Mac test runner
├── run-tests.ps1       # Windows test runner
├── vulnerable-app/     # Vulnerable version
│   ├── app.py
│   ├── Dockerfile
│   └── requirements.txt
└── patched-app/        # Fixed version
    ├── app.py
    ├── Dockerfile
    └── requirements.txt

References¶

https://github.com/kiteworks/security-advisories/security/advisories/GHSA-p435-6c3j-4gh5
https://raw.githubusercontent.com/cisagov/CSAF/develop/csaf_files/VA/white/2026/va-26-274-01.json

Generated by PoC Generator on 2026-10-04T09:39:23.097086151

Frequently asked questions¶

What is CVE-2026-102103?¶

CVE-2026-102103 is a Critical (9.1) vulnerability: Kiteworks Email Protection Gateway before version 9.5.0 is vulnerable to Server-Side…. This entry ships a detection-only PoC and a Docker test lab.

How do I detect CVE-2026-102103?¶

Run the detection-only PoC included with this entry against your Docker test lab to confirm whether a target is affected; pair it with your own IDS logging.

How do I block or mitigate CVE-2026-102103?¶

Upgrade to a fixed version per the vendor advisory; the NVD record lists the affected versions. Use the included PoC to verify your remediation.

For authorized security testing and research only. See the full source and NVD record.