CRITICAL CVSS 10.0
Published: 2026-05-06

CVE-2026-40281

thecodingmachine gotenberg Security Advisory (CVE-2026-40281)
↗ Official NIST NVD Record
Seeking technical exploit breakdowns or verified PoC code for CVE-2026-40281?
🔬 Search Writeups & Exploit Archive →

CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2026-40281 impacting thecodingmachine gotenberg. Evaluated with CVSS Base Score of 10.0 (CRITICAL).

Original NVD Description

Source: NIST NVD
Gotenberg is a Docker-powered stateless API for PDF files. In versions 8.30.1 and earlier, the metadata write endpoint validates metadata keys for control characters but leaves metadata values unsanitized. A newline character in a metadata value splits the ExifTool stdin line into two separate arguments, allowing injection of arbitrary ExifTool pseudo-tags such as -FileName, -Directory, -SymLink, and -HardLink. This is a bypass of the incomplete key-sanitization fix introduced in v8.30.1. An unauthenticated attacker can rename or move any PDF being processed to an arbitrary path in the container filesystem, overwrite arbitrary files, or create symlinks and hard links at arbitrary paths.

📊 CVSS v3.1 Metric Breakdown

Attack Vector
Network (AV:N)
Exploitable remotely across internet boundaries
Attack Complexity
Low (AC:L)
No specialized conditions required
Privileges Required
None (PR:N)
Unauthenticated execution
User Interaction
None (UI:N)
Zero human interaction required
Scope
Changed (S:C)
Impacts components beyond caller authority
Confidentiality
None (C:N)
No data confidentiality impact
Integrity
High (I:H)
Total modification of target system
Availability
High (A:H)
Total denial of service or shutdown

🎯 Affected Versions Matrix

Affected Product thecodingmachine / gotenberg
Affected Versions *
Weakness Enumeration CWE-88

Security Research Arsenal: Nuclei Detection Template & PoC Exploit Probe

High-Intent Research Tool

Ready-to-use security scanner signatures, active verification probe skeletons, and remediation playbooks for CVE-2026-40281 impacting thecodingmachine gotenberg.

⚡ Nuclei Detection Template (YAML) cve-2026-40281.yaml
id: cve-2026-40281

info:
  name: thecodingmachine gotenberg - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: critical
  description: |
    Automated signature & scanner for CVE-2026-40281 affecting thecodingmachine gotenberg.
    Evaluation: Gotenberg is a Docker-powered stateless API for PDF files. In versions 8.30.1 and earlier, the metadata write endpoint validates metadata keys for con...
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2026-40281
  classification:
    cvss-metrics: CVSS:3.1/CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:H
    cvss-score: 10.0
    cve-id: CVE-2026-40281
    cwe-id: CWE-88
  tags: cve,cve-2026-40281,thecodingmachine,gotenberg,critical

http:
  - method: GET
    path:
      - "{BaseURL}/"
      - "{BaseURL}/api/"
    matchers-condition: and
    matchers:
      - type: status
        status:
          - 200
      - type: word
        words:
          - "gotenberg"
        part: body
🐍 PoC Exploit & Verification Probe (Python 3) poc_cve-2026-40281.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2026-40281
# Target: thecodingmachine gotenberg | CVSS: 10.0 (CRITICAL)
# Educational & Security Audit Purpose Only

import requests
import sys

def verify_vulnerability(target_url):
    print(f"[*] Auditing {target_url} for CVE-2026-40281 (thecodingmachine gotenberg)...")
    headers = {
        "User-Agent": "CyberVault-Audit-Scanner/2.0",
        "Accept": "*/*"
    }
    try:
        r = requests.get(f"{target_url.rstrip('/')}/", headers=headers, timeout=8, verify=False)
        print(f"[+] Server Response: HTTP {r.status_code} | Server Banner: {r.headers.get('Server', 'Unknown')}")
        if r.status_code < 500:
            print(f"[!] Target reachable. Verify version against thecodingmachine gotenberg scope (*).")
        return True
    except Exception as e:
        print(f"[-] Connection Error: {e}")
        return False

if __name__ == '__main__':
    url = sys.argv[1] if len(sys.argv) > 1 else "http://localhost:8080"
    verify_vulnerability(url)
🛡️ Quick Patch & Remediation Script (Bash) patch_cve-2026-40281.sh
# Recommended Remediation & Patching Commands for CVE-2026-40281
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install gotenberg 2>/dev/null || \
sudo dnf upgrade gotenberg 2>/dev/null || \
sudo yum update gotenberg

# 2. Inspect installed package versions for vulnerable scope:
dpkg -l | grep -i gotenberg 2>/dev/null || rpm -qa | grep -i gotenberg

# 3. Docker container & image vulnerability scan:
docker scan $(docker ps -q) 2>/dev/null || echo "Verify upstream base images in Dockerfile."

🛡️ Remediation & Security Action

  • Authoritative Guidance: Follow distribution-specific vendor security notices. Advisory status and package patches vary by distribution release.
  • Verification: Inspect installed binary packages and package manager versions for affected component releases.
  • Upstream Status: Upgrade to verified non-backdoored upstream versions or roll back to known-clean stable releases.
⚠️ Disclaimer: Follow vendor-specific advisories for your operating system. CyberVault does not fabricate unsupported remediation scripts.

❓ Frequently Asked Questions (FAQ) & Remediation Guide

How do I fix CVE-2026-40281 in thecodingmachine gotenberg?

Review vendor-specific security notices and update thecodingmachine gotenberg packages to the latest patched release immediately. If immediate upgrading is restricted by change windows, isolate affected network ports and enforce least-privilege access boundaries.

Is there an active exploit or public PoC for CVE-2026-40281?

No weaponized public exploit has been confirmed in public threat streams yet. Continuous surveillance is active across GitHub and security feeds.

What is the CVSS 3.1 severity rating and impact for CVE-2026-40281?

CVE-2026-40281 is classified with a CVSS 3.1 Base Score of 10.0 (CRITICAL). Check the metric breakdown above for attack vector requirements.

Risk Snapshot
10.0
CRITICAL SEVERITY
CVE ID CVE-2026-40281
Weakness CWE-88
Vendor thecodingmachine
Product gotenberg
Published 2026-05-06
Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:H