CVE-2026-20335 — As part of Cisco's ongoing commitment to proactive security and product quality, the…¶

Key facts

CVE-2026-20335 is a High (8.1) vulnerability: As part of Cisco's ongoing commitment to proactive security and product quality, the…. This entry ships a detection-only PoC and a Docker test lab.


CVE	CVE-2026-20335
Severity	High (8.1)
Detection / prevention	—
PoC	poc.py
Source	2026/CVE-2026-20335/

Details¶

English | 한국어

Description¶

As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco Secure Adaptive Security Appliance Software, Cisco Secure Firewall Threat Defense Software and Cisco Secure Firewall Management Center Software engineering team has conducted a comprehensive internal security review. This review resulted in a software hardening release that addresses multiple internally discovered vulnerabilities.

The vulnerabilities tracked by CVE-2026-20335 are related to incorrect calculation issues that are grouped under the Common Weakness Enumeration (CWE) Pillar CWE-682.

Vulnerability Details¶

Property	Value
CVE ID	CVE-2026-20335
CVSS Score	8.1

Proof of Concept¶

Download¶

# Download PoC script
curl -O https://raw.githubusercontent.com/fankh/vulnerability-poc/main/2026/CVE-2026-20335/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-2026-20335

# 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://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-hardening-asaftdfmc-uvpPROhN

Generated by PoC Generator on 2026-09-18T20:46:02.11705795

Frequently asked questions¶

What is CVE-2026-20335?¶

CVE-2026-20335 is a High (8.1) vulnerability: As part of Cisco's ongoing commitment to proactive security and product quality, the…. This entry ships a detection-only PoC and a Docker test lab.

How do I detect CVE-2026-20335?¶

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-2026-20335?¶

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.