CVE-2026-54049 — Sakai is a Collaboration and Learning Environment (CLE).¶

Key facts

CVE-2026-54049 is a High (8.7) vulnerability: Sakai is a Collaboration and Learning Environment (CLE).. This entry ships a detection-only PoC and a Docker test lab.


CVE	CVE-2026-54049
Severity	High (8.7)
Detection / prevention	—
PoC	poc.py
Source	2026/CVE-2026-54049/

Details¶

English | 한국어

Description¶

Sakai is a Collaboration and Learning Environment (CLE). From versions 23.0 to before 23.5, and versions 25.0 to before 25.3, the Sakai Conversations tool stores topic and post messages without HTML sanitization, and the frontend renders them using LitElement's unsafeHTML() directive, resulting in stored cross-site scripting (XSS). Any authenticated user with access to a site that has the Conversations tool enabled can inject arbitrary HTML and JavaScript that executes in the browsers of all other users who view that topic or post. This issue has been patched in versions 23.5, 25.3, and 26.0.

Vulnerability Details¶

Property	Value
CVE ID	CVE-2026-54049
Type	XSS
CVSS Score	8.7

Proof of Concept¶

Download¶

# Download PoC script
curl -O https://raw.githubusercontent.com/fankh/vulnerability-poc/main/2026/CVE-2026-54049/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-2026-54049

# 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/sakaiproject/sakai/commit/2696b4b48cbef2e81512f52f84f7477adff78b27
https://github.com/sakaiproject/sakai/security/advisories/GHSA-w2x5-gv52-9ccv

Generated by PoC Generator on 2026-10-03T19:38:49.200799067

Frequently asked questions¶

What is CVE-2026-54049?¶

CVE-2026-54049 is a High (8.7) vulnerability: Sakai is a Collaboration and Learning Environment (CLE).. This entry ships a detection-only PoC and a Docker test lab.

How do I detect CVE-2026-54049?¶

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-2026-54049?¶

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.