MEDIUM CVSS 6.5
Published: 2026-04-08

CVE-2026-39414

minio minio Security Advisory (CVE-2026-39414)
↗ Official NIST NVD Record
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CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2026-39414 impacting minio minio. Evaluated with CVSS Base Score of 6.5 (MEDIUM).

Original NVD Description

Source: NIST NVD
MinIO is a high-performance object storage system. From RELEASE.2018-08-18T03-49-57Z to before RELEASE.2025-12-20T04-58-37Z, MinIO's S3 Select feature is vulnerable to memory exhaustion when processing CSV files containing lines longer than available memory. The CSV reader's nextSplit() function calls bufio.Reader.ReadBytes('\n') with no size limit, buffering the entire input in memory until a newline is found. A CSV file with no newline characters causes the entire contents to be read into a single allocation, leading to an OOM crash of the MinIO server process. This is exploitable by any authenticated user with s3:PutObject and s3:GetObject permissions. The attack is especially practical when combined with compression: a ~2 MB gzip-compressed CSV can decompress to gigabytes of data without newlines, allowing a small upload to cause large memory consumption on the server. However, compression is not required — a sufficiently large uncompressed CSV with no newlines triggers the same issue.

📊 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
None (C:N)
No data confidentiality impact
Integrity
None (I:N)
No system modification impact
Availability
High (A:H)
Total denial of service or shutdown

🎯 Affected Versions Matrix

Affected Product minio / minio
Affected Versions *
Weakness Enumeration CWE-770

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-2026-39414 impacting minio minio.

⚡ Nuclei Detection Template (YAML) cve-2026-39414.yaml
id: cve-2026-39414

info:
  name: minio minio - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: medium
  description: |
    Automated signature & scanner for CVE-2026-39414 affecting minio minio.
    Evaluation: MinIO is a high-performance object storage system. From RELEASE.2018-08-18T03-49-57Z to before RELEASE.2025-12-20T04-58-37Z, MinIO's S3 Select fe...
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2026-39414
  classification:
    cvss-metrics: CVSS:3.1/CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
    cvss-score: 6.5
    cve-id: CVE-2026-39414
    cwe-id: CWE-770
  tags: cve,cve-2026-39414,minio,minio,medium

http:
  - method: GET
    path:
      - "{BaseURL}/"
      - "{BaseURL}/api/"
    matchers-condition: and
    matchers:
      - type: status
        status:
          - 200
      - type: word
        words:
          - "minio"
        part: body
🐍 PoC Exploit & Verification Probe (Python 3) poc_cve-2026-39414.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2026-39414
# Target: minio minio | CVSS: 6.5 (MEDIUM)
# Educational & Security Audit Purpose Only

import requests
import sys

def verify_vulnerability(target_url):
    print(f"[*] Auditing {target_url} for CVE-2026-39414 (minio minio)...")
    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 minio minio 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-2026-39414.sh
# Recommended Remediation & Patching Commands for CVE-2026-39414
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install minio 2>/dev/null || \
sudo dnf upgrade minio 2>/dev/null || \
sudo yum update minio

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

# 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.

❓ Frequently Asked Questions (FAQ) & Remediation Guide

How do I fix CVE-2026-39414 in minio minio?

Review vendor-specific security notices and update minio minio 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-2026-39414?

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-2026-39414?

CVE-2026-39414 is classified with a CVSS 3.1 Base Score of 6.5 (MEDIUM). Check the metric breakdown above for attack vector requirements.

Risk Snapshot
6.5
MEDIUM SEVERITY
CVE ID CVE-2026-39414
Weakness CWE-770
Vendor minio
Product minio
Published 2026-04-08
Vector CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H