CVE-2026-42771
CyberVault Technical Summary
Analyst SynthesisTechnical analysis, exploit verification, and patch instructions for CVE-2026-42771 impacting openssl openssl. Evaluated with CVSS Base Score of 6.2 (MEDIUM).
Original NVD Description
Source: NIST NVD📊 CVSS v3.1 Metric Breakdown
🎯 Affected Versions Matrix
| Affected Product | openssl / openssl |
| Affected Versions | 4.0.0 |
| Weakness Enumeration | CWE-125 |
Security Research Arsenal: Nuclei Detection Template & PoC Exploit Probe
Ready-to-use security scanner signatures, active verification probe skeletons, and remediation playbooks for CVE-2026-42771 impacting openssl openssl.
id: cve-2026-42771
info:
name: openssl openssl - Security Advisory & Vulnerability Scan
author: cybervault-security-intel
severity: medium
description: |
Automated signature & scanner for CVE-2026-42771 affecting openssl openssl.
Evaluation: Issue summary: When the X509_VERIFY_PARAM_set1_email is called by an
application to validate a crafted e-mail address, such as during S/MIME
message v...
reference:
- https://cybervault-cve.pages.dev/cve/CVE-2026-42771
classification:
cvss-metrics: CVSS:3.1/CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
cvss-score: 6.2
cve-id: CVE-2026-42771
cwe-id: CWE-125
tags: cve,cve-2026-42771,openssl,openssl,medium
http:
- method: GET
path:
- "{BaseURL}/"
- "{BaseURL}/api/"
matchers-condition: and
matchers:
- type: status
status:
- 200
- type: word
words:
- "openssl"
part: body
# Proof-of-Concept Exploit & Verification Probe for CVE-2026-42771
# Target: openssl openssl | CVSS: 6.2 (MEDIUM)
# Educational & Security Audit Purpose Only
import requests
import sys
def verify_vulnerability(target_url):
print(f"[*] Auditing {target_url} for CVE-2026-42771 (openssl openssl)...")
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 openssl openssl scope (4.0.0).")
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)
# Recommended Remediation & Patching Commands for CVE-2026-42771
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install openssl 2>/dev/null || \
sudo dnf upgrade openssl 2>/dev/null || \
sudo yum update openssl
# 2. Inspect installed package versions for vulnerable scope:
dpkg -l | grep -i openssl 2>/dev/null || rpm -qa | grep -i openssl
# 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.
🔗 Verified Technical References
- No records filed in this category.
- No records filed in this category.
❓ Frequently Asked Questions (FAQ) & Remediation Guide
How do I fix CVE-2026-42771 in openssl openssl?
Review vendor-specific security notices and update openssl openssl 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-2026-42771?
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-2026-42771?
CVE-2026-42771 is classified with a CVSS 3.1 Base Score of 6.2 (MEDIUM). Check the metric breakdown above for attack vector requirements.