MEDIUM CVSS 6.0
Published: 2026-05-28

CVE-2026-42999

openstack keystone Security Advisory (CVE-2026-42999)
↗ Official NIST NVD Record
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CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2026-42999 impacting openstack keystone. Evaluated with CVSS Base Score of 6.0 (MEDIUM).

Original NVD Description

Source: NIST NVD
An issue was discovered in OpenStack Keystone before 29.0.2. The Keystone RBAC policy enforcer in enforce_call unconditionally merges the raw JSON request body into the policy enforcement dictionary via policy_dict.update(json_input.copy()), overwriting trusted target data that was previously set from database lookups. Because flask.request.get_json is called with force=True, this works regardless of Content-Type or HTTP method. Any authenticated user can inject arbitrary policy target attributes (e.g., user_id, project_id) into the request body to bypass RBAC checks and perform unauthorized operations on resources belonging to other users or projects. This was introduced in commit 5ea59f52 (Rocky/14.0.0).

📊 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
Low (PR:L)
Standard user access required
User Interaction
None (UI:N)
Zero human interaction required
Scope
Changed (S:C)
Impacts components beyond caller authority
Confidentiality
Low (C:L)
Partial information leakage
Integrity
Low (I:L)
Partial data modification possible
Availability
Low (A:L)
Partial service performance degradation

🎯 Affected Versions Matrix

Affected Product openstack / keystone
Affected Versions *
Weakness Enumeration CWE-863

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-2026-42999 impacting openstack keystone.

⚡ Nuclei Detection Template (YAML) cve-2026-42999.yaml
id: cve-2026-42999

info:
  name: openstack keystone - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: medium
  description: |
    Automated signature & scanner for CVE-2026-42999 affecting openstack keystone.
    Evaluation: An issue was discovered in OpenStack Keystone before 29.0.2. The Keystone RBAC policy enforcer in enforce_call unconditionally merges the raw JSON req...
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2026-42999
  classification:
    cvss-metrics: CVSS:3.1/CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:L/A:L
    cvss-score: 6.0
    cve-id: CVE-2026-42999
    cwe-id: CWE-863
  tags: cve,cve-2026-42999,openstack,keystone,medium

http:
  - method: GET
    path:
      - "{BaseURL}/"
      - "{BaseURL}/api/"
    matchers-condition: and
    matchers:
      - type: status
        status:
          - 200
      - type: word
        words:
          - "keystone"
        part: body
🐍 PoC Exploit & Verification Probe (Python 3) poc_cve-2026-42999.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2026-42999
# Target: openstack keystone | CVSS: 6.0 (MEDIUM)
# Educational & Security Audit Purpose Only

import requests
import sys

def verify_vulnerability(target_url):
    print(f"[*] Auditing {target_url} for CVE-2026-42999 (openstack keystone)...")
    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 openstack keystone 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-2026-42999.sh
# Recommended Remediation & Patching Commands for CVE-2026-42999
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install keystone 2>/dev/null || \
sudo dnf upgrade keystone 2>/dev/null || \
sudo yum update keystone

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

# 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-2026-42999 in openstack keystone?

Review vendor-specific security notices and update openstack keystone 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-2026-42999?

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-2026-42999?

CVE-2026-42999 is classified with a CVSS 3.1 Base Score of 6.0 (MEDIUM). Check the metric breakdown above for attack vector requirements.

Risk Snapshot
6.0
MEDIUM SEVERITY
CVE ID CVE-2026-42999
Weakness CWE-863
Vendor openstack
Product keystone
Published 2026-05-28
Vector CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:L/A:L