CVE-2026-102084 — An Improper Validation of Syntactic Correctness of Input vulnerability in the VPN daemon…¶

Key facts

CVE-2026-102084 is a High (8.1) vulnerability: An Improper Validation of Syntactic Correctness of Input vulnerability in the VPN daemon…. This entry ships a detection-only PoC and a Docker test lab.


CVE	CVE-2026-102084
Severity	High (8.1)
Detection / prevention	—
PoC	poc.py
Source	2026/CVE-2026-102084/

Details¶

English | 한국어

Description¶

An Improper Validation of Syntactic Correctness of Input vulnerability in the VPN daemon of Juniper Networks Junos OS on SRX Series allows an authenticated, network-based attacker to take complete control of the device.

If an SRX device configured for AutoDiscovery VPN (ADVPN) receives a message from a peer that contains one or more specifically malformed attributes, this will cause a buffer overflow, which can allow remote code execution and therefore allow an attacker to take complete control of the device. To be able to carry out this attack an attacker must either have acquired the shared secret to impersonate a peer or have compromised an existing one, so this attack is considerably difficult.

This issue affects Junos OS on SRX Series:

All versions before 23.2R2-S7.7;
from 23.4 before 23.4R2-S7;
from 24.2 before 24.2R2-S4;
from 24.4 before 24.4R2-S3;
from 25.2 before 25.2R2;
from 25.4 before 25.4R1-S3.

Vulnerability Details¶

Property	Value
CVE ID	CVE-2026-102084
Type	RCE
CVSS Score	8.1

Proof of Concept¶

Download¶

# Download PoC script
curl -O https://raw.githubusercontent.com/fankh/vulnerability-poc/main/2026/CVE-2026-102084/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-2026-102084

# 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://supportportal.juniper.net/JSA112173

Generated by PoC Generator on 2026-10-15T19:02:55.281431119

Frequently asked questions¶

What is CVE-2026-102084?¶

CVE-2026-102084 is a High (8.1) vulnerability: An Improper Validation of Syntactic Correctness of Input vulnerability in the VPN daemon…. This entry ships a detection-only PoC and a Docker test lab.

How do I detect CVE-2026-102084?¶

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-2026-102084?¶

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.