HIGH CVSS 7.7
Published: 2026-01-02

CVE-2026-21433

emlog emlog Security Advisory (CVE-2026-21433)
↗ Official NIST NVD Record
Seeking technical exploit breakdowns or verified PoC code for CVE-2026-21433?
🔬 Search Writeups & Exploit Archive →

CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2026-21433 impacting emlog emlog. Evaluated with CVSS Base Score of 7.7 (HIGH).

Original NVD Description

Source: NIST NVD
Emlog is an open source website building system. Versions up to and including 2.5.19 are vulnerable to server-side Out-of-Band (OOB) requests / SSRF via uploaded SVG files. An attacker can upload a crafted SVG to http[:]//emblog/admin/media[.]php which contains external resource references. When the server processes/renders the SVG (thumbnailing, preview, or sanitization), it issues an HTTP request to the attacker-controlled host. Impact: server-side SSRF/OOB leading to internal network probing and potential metadata/credential exposure. As of time of publication, no known patched versions are available.

📊 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
None (UI:N)
Zero human interaction required
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 emlog / emlog
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-2026-21433 impacting emlog emlog.

⚡ Nuclei Detection Template (YAML) cve-2026-21433.yaml
id: cve-2026-21433

info:
  name: emlog emlog - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: high
  description: |
    Automated signature & scanner for CVE-2026-21433 affecting emlog emlog.
    Evaluation: Emlog is an open source website building system. Versions up to and including 2.5.19 are vulnerable to server-side Out-of-Band (OOB) requests / SSRF v...
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2026-21433
  classification:
    cvss-metrics: CVSS:3.1/CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N
    cvss-score: 7.7
    cve-id: CVE-2026-21433
    cwe-id: CWE-918
  tags: cve,cve-2026-21433,emlog,emlog,high

http:
  - method: GET
    path:
      - "{BaseURL}/"
      - "{BaseURL}/api/"
    matchers-condition: and
    matchers:
      - type: status
        status:
          - 200
      - type: word
        words:
          - "emlog"
        part: body
🐍 PoC Exploit & Verification Probe (Python 3) poc_cve-2026-21433.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2026-21433
# Target: emlog emlog | CVSS: 7.7 (HIGH)
# Educational & Security Audit Purpose Only

import requests
import sys

def verify_vulnerability(target_url):
    print(f"[*] Auditing {target_url} for CVE-2026-21433 (emlog emlog)...")
    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 emlog emlog 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-2026-21433.sh
# Recommended Remediation & Patching Commands for CVE-2026-21433
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install emlog 2>/dev/null || \
sudo dnf upgrade emlog 2>/dev/null || \
sudo yum update emlog

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

# 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

Authorities
  • No records filed in this category.
Distributions
  • No records filed in this category.

❓ Frequently Asked Questions (FAQ) & Remediation Guide

How do I fix CVE-2026-21433 in emlog emlog?

Review vendor-specific security notices and update emlog emlog 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-2026-21433?

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-2026-21433?

CVE-2026-21433 is classified with a CVSS 3.1 Base Score of 7.7 (HIGH). Check the metric breakdown above for attack vector requirements.

Risk Snapshot
7.7
HIGH SEVERITY
CVE ID CVE-2026-21433
Weakness CWE-918
Vendor emlog
Product emlog
Published 2026-01-02
Vector CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N