CVE-2026-48026 — lakeFS is an open-source tool that transforms object storage into a Git-like repositories.¶

Key facts

CVE-2026-48026 is a High (8.7) vulnerability: lakeFS is an open-source tool that transforms object storage into a Git-like repositories.. This entry ships a detection-only PoC and a Docker test lab.


CVE	CVE-2026-48026
Severity	High (8.7)
Detection / prevention	—
PoC	poc.py
Source	2026/CVE-2026-48026/

Details¶

English | 한국어

Description¶

lakeFS is an open-source tool that transforms object storage into a Git-like repositories. Prior to version 1.81.1 of the open source edition and 1.84.0 of the enterprise edition, lakeFS Web UI renders markdown files from repository objects without sanitizing the resulting HTML. A user with write access to any repository branch can commit a .md object containing arbitrary HTML/JavaScript. Any other user who opens that object, or who navigates to a repository or directory containing a malicious README.md, executes the attacker-supplied script in their own authenticated session. lakeFS fixes the issue in v1.81.1 and lakeFS Enterprise fixes the issue in in v1.84.0. Enterprise customers using older versions can temporarily disable Markdown rendering by adding YAML to their config. No workaround exists for OSS release. Users are advised to upgrade to the latest version for both lakeFS and lakeFS-Enterprise.

Vulnerability Details¶

Property	Value
CVE ID	CVE-2026-48026
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-2026-48026/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-2026-48026

# 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/treeverse/lakeFS/blob/77539527e987fb05c27e3e74c59c0a46a05c47a0/webui/src/pages/repositories/repository/fileRenderers/useMarkdownProcessor.tsx
https://github.com/treeverse/lakeFS/security/advisories/GHSA-c2r5-5j4w-2xff

Generated by PoC Generator on 2026-08-08T09:10:04.233280898

Frequently asked questions¶

What is CVE-2026-48026?¶

CVE-2026-48026 is a High (8.7) vulnerability: lakeFS is an open-source tool that transforms object storage into a Git-like repositories.. This entry ships a detection-only PoC and a Docker test lab.

How do I detect CVE-2026-48026?¶

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-2026-48026?¶

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.