CVE-2026-45695 — Kopia is a cross-platform backup tool for Windows, macOS, and Linux with fast incremental…¶

Key facts

CVE-2026-45695 is a Critical (9.8) vulnerability: Kopia is a cross-platform backup tool for Windows, macOS, and Linux with fast incremental…. This entry ships a detection-only PoC and a Docker test lab.


CVE	CVE-2026-45695
Severity	Critical (9.8)
Detection / prevention	—
PoC	poc.py
Source	2026/CVE-2026-45695/

Details¶

English | 한국어

Description¶

Kopia is a cross-platform backup tool for Windows, macOS, and Linux with fast incremental backups, client-side end-to-end encryption, compression, and data deduplication. Prior to 0.23.0, Kopia's HTTP server started with --without-password accepts unauthenticated requests to /api/v1/repo/exists and forwards attacker-supplied SFTP storage configuration to blob.NewStorage, where externalSSH: true and sshArguments containing -oProxyCommand= can cause exec.CommandContext("ssh") to invoke the command through OpenSSH. This issue is fixed in version 0.23.0.

Vulnerability Details¶

Property	Value
CVE ID	CVE-2026-45695
Type	RCE
CVSS Score	9.8

Proof of Concept¶

Download¶

# Download PoC script
curl -O https://raw.githubusercontent.com/fankh/vulnerability-poc/main/2026/CVE-2026-45695/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-2026-45695

# 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/kopia/kopia/commit/c26c6a1b9734c5089217986ffa5cd19f8a6b8900
https://github.com/kopia/kopia/pull/5354
https://github.com/kopia/kopia/releases/tag/v0.23.0
https://github.com/kopia/kopia/security/advisories/GHSA-2q4c-3mrw-63c3

Generated by PoC Generator on 2026-07-17T15:23:47.590612898

Frequently asked questions¶

What is CVE-2026-45695?¶

CVE-2026-45695 is a Critical (9.8) vulnerability: Kopia is a cross-platform backup tool for Windows, macOS, and Linux with fast incremental…. This entry ships a detection-only PoC and a Docker test lab.

How do I detect CVE-2026-45695?¶

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-2026-45695?¶

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.