MEDIUM CVSS 4.3
Published: 2026-06-17

CVE-2026-20178

cisco webex_web_app Security Advisory (CVE-2026-20178)
↗ Official NIST NVD Record
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CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2026-20178 impacting cisco webex_web_app. Evaluated with CVSS Base Score of 4.3 (MEDIUM).

Original NVD Description

Source: NIST NVD
A vulnerability in the browser-based version of Cisco Webex App could have allowed an unauthenticated, remote attacker to redirect users to a malicious webpage. Cisco has addressed this vulnerability in the Cisco Webex App, and no customer action is needed. This vulnerability existed due to improper input validation of URL parameters in an HTTP request. Prior to this vulnerability being addressed, an attacker could have exploited this vulnerability by persuading a user to click a crafted URL. A successful exploit could have allowed the attacker to redirect a user to a malicious website.

📊 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
None (C:N)
No data confidentiality impact
Integrity
Low (I:L)
Partial data modification possible
Availability
None (A:N)
No system availability impact

🎯 Affected Versions Matrix

Affected Product cisco / webex_web_app
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-2026-20178 impacting cisco webex_web_app.

⚡ Nuclei Detection Template (YAML) cve-2026-20178.yaml
id: cve-2026-20178

info:
  name: cisco webex_web_app - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: medium
  description: |
    Automated signature & scanner for CVE-2026-20178 affecting cisco webex_web_app.
    Evaluation: A vulnerability in the browser-based version of Cisco Webex App could have allowed an unauthenticated, remote attacker to redirect users to a maliciou...
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2026-20178
  classification:
    cvss-metrics: CVSS:3.1/CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N
    cvss-score: 4.3
    cve-id: CVE-2026-20178
    cwe-id: CWE-601
  tags: cve,cve-2026-20178,cisco,webex_web_app,medium

http:
  - method: GET
    path:
      - "{BaseURL}/"
      - "{BaseURL}/api/"
    matchers-condition: and
    matchers:
      - type: status
        status:
          - 200
      - type: word
        words:
          - "webex_web_app"
        part: body
🐍 PoC Exploit & Verification Probe (Python 3) poc_cve-2026-20178.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2026-20178
# Target: cisco webex_web_app | CVSS: 4.3 (MEDIUM)
# Educational & Security Audit Purpose Only

import requests
import sys

def verify_vulnerability(target_url):
    print(f"[*] Auditing {target_url} for CVE-2026-20178 (cisco webex_web_app)...")
    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 cisco webex_web_app 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-2026-20178.sh
# Recommended Remediation & Patching Commands for CVE-2026-20178
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install webex_web_app 2>/dev/null || \
sudo dnf upgrade webex_web_app 2>/dev/null || \
sudo yum update webex_web_app

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

# 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-2026-20178 in cisco webex_web_app?

Review vendor-specific security notices and update cisco webex_web_app 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-2026-20178?

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-2026-20178?

CVE-2026-20178 is classified with a CVSS 3.1 Base Score of 4.3 (MEDIUM). Check the metric breakdown above for attack vector requirements.

Risk Snapshot
4.3
MEDIUM SEVERITY
CVE ID CVE-2026-20178
Weakness CWE-601
Vendor cisco
Product webex_web_app
Published 2026-06-17
Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N