MEDIUM CVSS 5.9
Published: 2026-07-06

CVE-2026-54291

postgresql postgresql_jdbc_driver Security Advisory (CVE-2026-54291)
↗ Official NIST NVD Record
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CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2026-54291 impacting postgresql postgresql_jdbc_driver. Evaluated with CVSS Base Score of 5.9 (MEDIUM).

Original NVD Description

Source: NIST NVD
pgjdbc is an open source postgresql JDBC Driver. In releases 42.7.4 through 42.7.11, channelBinding=require connections can be silently downgraded from SCRAM-SHA-256-PLUS with channel binding to plain SCRAM-SHA-256 without it, losing the man-in-the-middle protection the setting is meant to guarantee. An attacker who can intercept the TLS connection can trigger the downgrade with a certificate whose signature algorithm has no tls-server-end-point channel-binding hash, because the bundled com.ongres.scram:scram-client returns an empty byte array instead of failing and pgJDBC ScramAuthenticator checks only that the server advertised a PLUS mechanism, without rejecting the empty binding or checking that the negotiated mechanism uses channel binding. This issue is fixed in version 42.7.12.

📊 CVSS v3.1 Metric Breakdown

Attack Vector
Network (AV:N)
Exploitable remotely across internet boundaries
Attack Complexity
High (AC:H)
Depends on race conditions or environment
Privileges Required
None (PR:N)
Unauthenticated execution
User Interaction
None (UI:N)
Zero human interaction required
Scope
Unchanged (S:U)
Confined to same security context
Confidentiality
None (C:N)
No data confidentiality impact
Integrity
High (I:H)
Total modification of target system
Availability
None (A:N)
No system availability impact

🎯 Affected Versions Matrix

Affected Product postgresql / postgresql_jdbc_driver
Affected Versions *
Weakness Enumeration CWE-636

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-2026-54291 impacting postgresql postgresql_jdbc_driver.

⚡ Nuclei Detection Template (YAML) cve-2026-54291.yaml
id: cve-2026-54291

info:
  name: postgresql postgresql_jdbc_driver - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: medium
  description: |
    Automated signature & scanner for CVE-2026-54291 affecting postgresql postgresql_jdbc_driver.
    Evaluation: pgjdbc is an open source postgresql JDBC Driver. In releases 42.7.4 through 42.7.11, channelBinding=require connections can be silently downgraded fro...
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2026-54291
  classification:
    cvss-metrics: CVSS:3.1/CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N
    cvss-score: 5.9
    cve-id: CVE-2026-54291
    cwe-id: CWE-636
  tags: cve,cve-2026-54291,postgresql,postgresql_jdbc_driver,medium

http:
  - method: GET
    path:
      - "{BaseURL}/"
      - "{BaseURL}/api/"
    matchers-condition: and
    matchers:
      - type: status
        status:
          - 200
      - type: word
        words:
          - "postgresql_jdbc_driver"
        part: body
🐍 PoC Exploit & Verification Probe (Python 3) poc_cve-2026-54291.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2026-54291
# Target: postgresql postgresql_jdbc_driver | CVSS: 5.9 (MEDIUM)
# Educational & Security Audit Purpose Only

import requests
import sys

def verify_vulnerability(target_url):
    print(f"[*] Auditing {target_url} for CVE-2026-54291 (postgresql postgresql_jdbc_driver)...")
    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 postgresql postgresql_jdbc_driver 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-2026-54291.sh
# Recommended Remediation & Patching Commands for CVE-2026-54291
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install postgresql_jdbc_driver 2>/dev/null || \
sudo dnf upgrade postgresql_jdbc_driver 2>/dev/null || \
sudo yum update postgresql_jdbc_driver

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

# 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-2026-54291 in postgresql postgresql_jdbc_driver?

Review vendor-specific security notices and update postgresql postgresql_jdbc_driver 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-2026-54291?

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-2026-54291?

CVE-2026-54291 is classified with a CVSS 3.1 Base Score of 5.9 (MEDIUM). Check the metric breakdown above for attack vector requirements.

Risk Snapshot
5.9
MEDIUM SEVERITY
CVE ID CVE-2026-54291
Weakness CWE-636
Vendor postgresql
Product postgresql_jdbc_driver
Published 2026-07-06
Vector CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N