MEDIUM CVSS 4.3
Published: 2026-06-24

CVE-2026-57300

jenkins mcp_server Security Advisory (CVE-2026-57300)
↗ Official NIST NVD Record
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CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2026-57300 impacting jenkins mcp_server. Evaluated with CVSS Base Score of 4.3 (MEDIUM).

Original NVD Description

Source: NIST NVD
A missing permission check in Jenkins MCP Server Plugin 0.177.v629fdb_2557fe and earlier allows attackers with Item/Read permission to read the Pipeline replay scripts of jobs they can access.

📊 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
Unchanged (S:U)
Confined to same security context
Confidentiality
Low (C:L)
Partial information leakage
Integrity
None (I:N)
No system modification impact
Availability
None (A:N)
No system availability impact

🎯 Affected Versions Matrix

Affected Product jenkins / mcp_server
Affected Versions *
Weakness Enumeration CWE-862

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-2026-57300 impacting jenkins mcp_server.

⚡ Nuclei Detection Template (YAML) cve-2026-57300.yaml
id: cve-2026-57300

info:
  name: jenkins mcp_server - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: medium
  description: |
    Automated signature & scanner for CVE-2026-57300 affecting jenkins mcp_server.
    Evaluation: A missing permission check in Jenkins MCP Server Plugin 0.177.v629fdb_2557fe and earlier allows attackers with Item/Read permission to read the Pipeli...
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2026-57300
  classification:
    cvss-metrics: CVSS:3.1/CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
    cvss-score: 4.3
    cve-id: CVE-2026-57300
    cwe-id: CWE-862
  tags: cve,cve-2026-57300,jenkins,mcp_server,medium

http:
  - method: GET
    path:
      - "{BaseURL}/"
      - "{BaseURL}/api/"
    matchers-condition: and
    matchers:
      - type: status
        status:
          - 200
      - type: word
        words:
          - "mcp_server"
        part: body
🐍 PoC Exploit & Verification Probe (Python 3) poc_cve-2026-57300.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2026-57300
# Target: jenkins mcp_server | 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-2026-57300 (jenkins mcp_server)...")
    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 jenkins mcp_server 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-2026-57300.sh
# Recommended Remediation & Patching Commands for CVE-2026-57300
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install mcp_server 2>/dev/null || \
sudo dnf upgrade mcp_server 2>/dev/null || \
sudo yum update mcp_server

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

# 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-2026-57300 in jenkins mcp_server?

Review vendor-specific security notices and update jenkins mcp_server 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-2026-57300?

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-2026-57300?

CVE-2026-57300 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-2026-57300
Weakness CWE-862
Vendor jenkins
Product mcp_server
Published 2026-06-24
Vector CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N