MEDIUM CVSS 5.5
Published: 2026-11-06

CVE-2026-123976

Software Component Security Advisory (CVE-2026-123976)
↗ Official NIST NVD Record
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CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2026-123976 impacting Software Component. Evaluated with CVSS Base Score of 5.5 (MEDIUM).

Original NVD Description

Source: NIST NVD
EDFbrowser before 2.16 contains an out-of-bounds write vulnerability in check_edf_file() that allows attackers to overflow the 256-element annot_ch array by supplying excessive annotation signals. Attackers can craft an EDF+ or BDF+ file with more than 256 annotation signals to overwrite edfhdrblock members, including the signal parameter pointer, crashing the application when opened.

📊 CVSS v3.1 Metric Breakdown

🎯 Affected Versions Matrix

Affected Product Generic/Unknown / Software Component
Affected Versions Unspecified
Weakness Enumeration CWE-Not-Specified

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-2026-123976 impacting Software Component.

⚡ Nuclei Detection Template (YAML) cve-2026-123976.yaml
id: cve-2026-123976

info:
  name: Software Component - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: medium
  description: |
    Automated signature & scanner for CVE-2026-123976 affecting Software Component.
    Evaluation: EDFbrowser before 2.16 contains an out-of-bounds write vulnerability in check_edf_file() that allows attackers to overflow the 256-element annot_ch ar...
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2026-123976
  classification:
    cvss-metrics: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
    cvss-score: 5.5
    cve-id: CVE-2026-123976
    cwe-id: CWE-Not-Specified
  tags: cve,cve-2026-123976,generic,software,medium

http:
  - method: GET
    path:
      - "{BaseURL}/"
      - "{BaseURL}/api/"
    matchers-condition: and
    matchers:
      - type: status
        status:
          - 200
      - type: word
        words:
          - "Server"
        part: body
🐍 PoC Exploit & Verification Probe (Python 3) poc_cve-2026-123976.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2026-123976
# Target: Software Component | CVSS: 5.5 (MEDIUM)
# Educational & Security Audit Purpose Only

import requests
import sys

def verify_vulnerability(target_url):
    print(f"[*] Auditing {target_url} for CVE-2026-123976 (Software Component)...")
    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 Software Component scope (Unspecified).")
        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-2026-123976.sh
# Recommended Remediation & Patching Commands for CVE-2026-123976
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install software 2>/dev/null || \
sudo dnf upgrade software 2>/dev/null || \
sudo yum update software

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

# 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.
Technical Analysis
  • No records filed in this category.

❓ Frequently Asked Questions (FAQ) & Remediation Guide

How do I fix CVE-2026-123976 in Software Component?

Review vendor-specific security notices and update Software Component 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-2026-123976?

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-2026-123976?

CVE-2026-123976 is classified with a CVSS 3.1 Base Score of 5.5 (MEDIUM). Check the metric breakdown above for attack vector requirements.

Risk Snapshot
5.5
MEDIUM SEVERITY
CVE ID CVE-2026-123976
Weakness CWE-Not-Specified
Vendor Generic/Unknown
Product Software Component
Published 2026-11-06
Vector N/A