HIGH CVSS 7.8
Published: 2026-05-28

CVE-2026-49237

canonical multipass Security Advisory (CVE-2026-49237)
↗ Official NIST NVD Record
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CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2026-49237 impacting canonical multipass. Evaluated with CVSS Base Score of 7.8 (HIGH).

Original NVD Description

Source: NIST NVD
An issue was discovered in Canonical Multipass for macOS before version 1.16.3 due to an incomplete fix for CVE-2025-5199. While the patch in version 1.16.0 updated the ownership of the multipassd daemon binary to root:wheel, five co-located binaries (multipass, qemu-img, qemu-system-aarch64, qemu-system-x86_64, and sshfs_server) in /Library/Application Support/com.canonical.multipass/bin/ retain ownership by the installing user and remain writable. Because the root LaunchDaemon (com.canonical.multipassd.plist) configures a PATH environment variable that prioritizes this user-writable directory and invokes these auxiliary binaries by their bare names, a local attacker can replace an auxiliary binary (such as qemu-img) with a malicious wrapper. When the root daemon subsequently triggers the binary during routine execution (e.g., via multipass launch), the malicious code executes with root privileges, leading to local privilege escalation.

📊 CVSS v3.1 Metric Breakdown

Attack Vector
Local (AV:L)
Requires local system execution permissions
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
High (C:H)
Total information disclosure
Integrity
High (I:H)
Total modification of target system
Availability
High (A:H)
Total denial of service or shutdown

🎯 Affected Versions Matrix

Affected Product canonical / multipass
Affected Versions *
Weakness Enumeration CWE-276

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-2026-49237 impacting canonical multipass.

⚡ Nuclei Detection Template (YAML) cve-2026-49237.yaml
id: cve-2026-49237

info:
  name: canonical multipass - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: high
  description: |
    Automated signature & scanner for CVE-2026-49237 affecting canonical multipass.
    Evaluation: An issue was discovered in Canonical Multipass for macOS before version 1.16.3 due to an incomplete fix for CVE-2025-5199. While the patch in version ...
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2026-49237
  classification:
    cvss-metrics: CVSS:3.1/CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
    cvss-score: 7.8
    cve-id: CVE-2026-49237
    cwe-id: CWE-276
  tags: cve,cve-2026-49237,canonical,multipass,high

http:
  - method: GET
    path:
      - "{BaseURL}/"
      - "{BaseURL}/api/"
    matchers-condition: and
    matchers:
      - type: status
        status:
          - 200
      - type: word
        words:
          - "multipass"
        part: body
🐍 PoC Exploit & Verification Probe (Python 3) poc_cve-2026-49237.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2026-49237
# Target: canonical multipass | CVSS: 7.8 (HIGH)
# Educational & Security Audit Purpose Only

import requests
import sys

def verify_vulnerability(target_url):
    print(f"[*] Auditing {target_url} for CVE-2026-49237 (canonical multipass)...")
    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 canonical multipass 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-2026-49237.sh
# Recommended Remediation & Patching Commands for CVE-2026-49237
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install multipass 2>/dev/null || \
sudo dnf upgrade multipass 2>/dev/null || \
sudo yum update multipass

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

# 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-2026-49237 in canonical multipass?

Review vendor-specific security notices and update canonical multipass 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-2026-49237?

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-2026-49237?

CVE-2026-49237 is classified with a CVSS 3.1 Base Score of 7.8 (HIGH). Check the metric breakdown above for attack vector requirements.

Risk Snapshot
7.8
HIGH SEVERITY
CVE ID CVE-2026-49237
Weakness CWE-276
Vendor canonical
Product multipass
Published 2026-05-28
Vector CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H