CRITICAL CVSS 9.1
Published: 2026-03-20

CVE-2026-33210

ruby-lang json Security Advisory (CVE-2026-33210)
↗ Official NIST NVD Record
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CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2026-33210 impacting ruby-lang json. Evaluated with CVSS Base Score of 9.1 (CRITICAL).

Original NVD Description

Source: NIST NVD
Ruby JSON is a JSON implementation for Ruby. From version 2.14.0 to before versions 2.15.2.1, 2.17.1.2, and 2.19.2, a format string injection vulnerability can lead to denial of service attacks or information disclosure, when the allow_duplicate_key: false parsing option is used to parse user supplied documents. This issue has been patched in versions 2.15.2.1, 2.17.1.2, and 2.19.2.

📊 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
None (UI:N)
Zero human interaction required
Scope
Unchanged (S:U)
Confined to same security context
Confidentiality
High (C:H)
Total information disclosure
Integrity
None (I:N)
No system modification impact
Availability
High (A:H)
Total denial of service or shutdown

🎯 Affected Versions Matrix

Affected Product ruby-lang / json
Affected Versions *
Weakness Enumeration CWE-134

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-2026-33210 impacting ruby-lang json.

⚡ Nuclei Detection Template (YAML) cve-2026-33210.yaml
id: cve-2026-33210

info:
  name: ruby-lang json - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: critical
  description: |
    Automated signature & scanner for CVE-2026-33210 affecting ruby-lang json.
    Evaluation: Ruby JSON is a JSON implementation for Ruby. From version 2.14.0 to before versions 2.15.2.1, 2.17.1.2, and 2.19.2, a format string injection vulnerab...
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2026-33210
  classification:
    cvss-metrics: CVSS:3.1/CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
    cvss-score: 9.1
    cve-id: CVE-2026-33210
    cwe-id: CWE-134
  tags: cve,cve-2026-33210,ruby-lang,json,critical

http:
  - method: GET
    path:
      - "{BaseURL}/"
      - "{BaseURL}/api/"
    matchers-condition: and
    matchers:
      - type: status
        status:
          - 200
      - type: word
        words:
          - "json"
        part: body
🐍 PoC Exploit & Verification Probe (Python 3) poc_cve-2026-33210.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2026-33210
# Target: ruby-lang json | CVSS: 9.1 (CRITICAL)
# Educational & Security Audit Purpose Only

import requests
import sys

def verify_vulnerability(target_url):
    print(f"[*] Auditing {target_url} for CVE-2026-33210 (ruby-lang json)...")
    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 ruby-lang json 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-2026-33210.sh
# Recommended Remediation & Patching Commands for CVE-2026-33210
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install json 2>/dev/null || \
sudo dnf upgrade json 2>/dev/null || \
sudo yum update json

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

# 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-2026-33210 in ruby-lang json?

Review vendor-specific security notices and update ruby-lang json 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-2026-33210?

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-2026-33210?

CVE-2026-33210 is classified with a CVSS 3.1 Base Score of 9.1 (CRITICAL). Check the metric breakdown above for attack vector requirements.

Risk Snapshot
9.1
CRITICAL SEVERITY
CVE ID CVE-2026-33210
Weakness CWE-134
Vendor ruby-lang
Product json
Published 2026-03-20
Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H