MEDIUM CVSS 5.4
Published: 2026-06-10

CVE-2026-46616

umbraco umbraco_cms Security Advisory (CVE-2026-46616)
↗ Official NIST NVD Record
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CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2026-46616 impacting umbraco umbraco_cms. Evaluated with CVSS Base Score of 5.4 (MEDIUM).

Original NVD Description

Source: NIST NVD
Umbraco is an ASP.NET CMS. Prior to versions 13.14.0 and 17.4.0, some of the Surface Controllers in the CMS provide to support member related operations fail to validate redirect URLs, making Razor templates that derive 'RedirectUrl' from user-controlled query parameters vulnerable to malicious redirect attacks. This issue has been patched in versions 13.14.0 and 17.4.0.

📊 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
Required (UI:R)
User must click or open resource
Scope
Unchanged (S:U)
Confined to same security context
Confidentiality
Low (C:L)
Partial information leakage
Integrity
Low (I:L)
Partial data modification possible
Availability
None (A:N)
No system availability impact

🎯 Affected Versions Matrix

Affected Product umbraco / umbraco_cms
Affected Versions *
Weakness Enumeration CWE-601

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-2026-46616 impacting umbraco umbraco_cms.

⚡ Nuclei Detection Template (YAML) cve-2026-46616.yaml
id: cve-2026-46616

info:
  name: umbraco umbraco_cms - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: medium
  description: |
    Automated signature & scanner for CVE-2026-46616 affecting umbraco umbraco_cms.
    Evaluation: Umbraco is an ASP.NET CMS. Prior to versions 13.14.0 and 17.4.0, some of the Surface Controllers in the CMS provide to support member related operatio...
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2026-46616
  classification:
    cvss-metrics: CVSS:3.1/CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N
    cvss-score: 5.4
    cve-id: CVE-2026-46616
    cwe-id: CWE-601
  tags: cve,cve-2026-46616,umbraco,umbraco_cms,medium

http:
  - method: GET
    path:
      - "{BaseURL}/"
      - "{BaseURL}/api/"
    matchers-condition: and
    matchers:
      - type: status
        status:
          - 200
      - type: word
        words:
          - "umbraco_cms"
        part: body
🐍 PoC Exploit & Verification Probe (Python 3) poc_cve-2026-46616.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2026-46616
# Target: umbraco umbraco_cms | CVSS: 5.4 (MEDIUM)
# Educational & Security Audit Purpose Only

import requests
import sys

def verify_vulnerability(target_url):
    print(f"[*] Auditing {target_url} for CVE-2026-46616 (umbraco umbraco_cms)...")
    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 umbraco umbraco_cms 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-2026-46616.sh
# Recommended Remediation & Patching Commands for CVE-2026-46616
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install umbraco_cms 2>/dev/null || \
sudo dnf upgrade umbraco_cms 2>/dev/null || \
sudo yum update umbraco_cms

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

# 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.

🔗 Verified Technical References

❓ Frequently Asked Questions (FAQ) & Remediation Guide

How do I fix CVE-2026-46616 in umbraco umbraco_cms?

Review vendor-specific security notices and update umbraco umbraco_cms 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-2026-46616?

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-2026-46616?

CVE-2026-46616 is classified with a CVSS 3.1 Base Score of 5.4 (MEDIUM). Check the metric breakdown above for attack vector requirements.

Risk Snapshot
5.4
MEDIUM SEVERITY
CVE ID CVE-2026-46616
Weakness CWE-601
Vendor umbraco
Product umbraco_cms
Published 2026-06-10
Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N