MEDIUM CVSS 6.8
Published: 2026-07-06

CVE-2026-58404

gohugo hugo Security Advisory (CVE-2026-58404)
↗ Official NIST NVD Record
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CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2026-58404 impacting gohugo hugo. Evaluated with CVSS Base Score of 6.8 (MEDIUM).

Original NVD Description

Source: NIST NVD
Hugo is a static site generator. From v0.162.0 through v0.163.0, the default security.http.urls policy denies requests to loopback, internal, and cloud-metadata IPv4 literals, but the deny rule only matched dotted-decimal notation, so alternate IPv4 encodings of the same addresses, including integer, hex, or octal, passed the policy. When a template passes an untrusted or data-derived URL to resources.GetRemote and the host platform uses the cgo system resolver, these encodings resolve to the blocked address, allowing build-time server-side requests to loopback and internal services, including the cloud-metadata endpoint in hosted or CI builds; the same check is reused on redirects, so the gap also applies to each redirect hop. This issue is fixed in v0.163.1.

📊 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
Low (PR:L)
Standard user access required
User Interaction
Required (UI:R)
User must click or open resource
Scope
Changed (S:C)
Impacts components beyond caller authority
Confidentiality
High (C:H)
Total information disclosure
Integrity
None (I:N)
No system modification impact
Availability
None (A:N)
No system availability impact

🎯 Affected Versions Matrix

Affected Product gohugo / hugo
Affected Versions *
Weakness Enumeration CWE-918

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-2026-58404 impacting gohugo hugo.

⚡ Nuclei Detection Template (YAML) cve-2026-58404.yaml
id: cve-2026-58404

info:
  name: gohugo hugo - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: medium
  description: |
    Automated signature & scanner for CVE-2026-58404 affecting gohugo hugo.
    Evaluation: Hugo is a static site generator. From v0.162.0 through v0.163.0, the default security.http.urls policy denies requests to loopback, internal, and clou...
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2026-58404
  classification:
    cvss-metrics: CVSS:3.1/CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:N/A:N
    cvss-score: 6.8
    cve-id: CVE-2026-58404
    cwe-id: CWE-918
  tags: cve,cve-2026-58404,gohugo,hugo,medium

http:
  - method: GET
    path:
      - "{BaseURL}/"
      - "{BaseURL}/api/"
    matchers-condition: and
    matchers:
      - type: status
        status:
          - 200
      - type: word
        words:
          - "hugo"
        part: body
🐍 PoC Exploit & Verification Probe (Python 3) poc_cve-2026-58404.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2026-58404
# Target: gohugo hugo | CVSS: 6.8 (MEDIUM)
# Educational & Security Audit Purpose Only

import requests
import sys

def verify_vulnerability(target_url):
    print(f"[*] Auditing {target_url} for CVE-2026-58404 (gohugo hugo)...")
    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 gohugo hugo 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-2026-58404.sh
# Recommended Remediation & Patching Commands for CVE-2026-58404
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install hugo 2>/dev/null || \
sudo dnf upgrade hugo 2>/dev/null || \
sudo yum update hugo

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

# 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-2026-58404 in gohugo hugo?

Review vendor-specific security notices and update gohugo hugo 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-2026-58404?

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-2026-58404?

CVE-2026-58404 is classified with a CVSS 3.1 Base Score of 6.8 (MEDIUM). Check the metric breakdown above for attack vector requirements.

Risk Snapshot
6.8
MEDIUM SEVERITY
CVE ID CVE-2026-58404
Weakness CWE-918
Vendor gohugo
Product hugo
Published 2026-07-06
Vector CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:N/A:N