MEDIUM CVSS 5.3
Published: 2025-07-29

CVE-2025-54126

bytecodealliance webassembly_micro_runtime Security Advisory (CVE-2025-54126)
↗ Official NIST NVD Record
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CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2025-54126 impacting bytecodealliance webassembly_micro_runtime. Evaluated with CVSS Base Score of 5.3 (MEDIUM).

Original NVD Description

Source: NIST NVD
The WebAssembly Micro Runtime's (WAMR) iwasm package is the executable binary built with WAMR VMcore which supports WebAssembly System Interface (WASI) and command line interface. In versions 2.4.0 and below, iwasm uses --addr-pool with an IPv4 address that lacks a subnet mask, allowing the system to accept all IP addresses. This can unintentionally expose the service to all incoming connections and bypass intended access restrictions. Services relying on --addr-pool for restricting access by IP may unintentionally become open to all external connections. This may lead to unauthorized access in production deployments, especially when users assume that specifying an IP without a subnet mask implies a default secure configuration. This is fixed in version 2.4.1.

📊 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
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 bytecodealliance / webassembly_micro_runtime
Affected Versions *
Weakness Enumeration CWE-668

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-2025-54126 impacting bytecodealliance webassembly_micro_runtime.

⚡ Nuclei Detection Template (YAML) cve-2025-54126.yaml
id: cve-2025-54126

info:
  name: bytecodealliance webassembly_micro_runtime - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: medium
  description: |
    Automated signature & scanner for CVE-2025-54126 affecting bytecodealliance webassembly_micro_runtime.
    Evaluation: The WebAssembly Micro Runtime's (WAMR) iwasm package is the executable binary built with WAMR VMcore which supports WebAssembly System Interface ...
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2025-54126
  classification:
    cvss-metrics: CVSS:3.1/CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
    cvss-score: 5.3
    cve-id: CVE-2025-54126
    cwe-id: CWE-668
  tags: cve,cve-2025-54126,bytecodealliance,webassembly_micro_runtime,medium

http:
  - method: GET
    path:
      - "{BaseURL}/"
      - "{BaseURL}/api/"
    matchers-condition: and
    matchers:
      - type: status
        status:
          - 200
      - type: word
        words:
          - "webassembly_micro_runtime"
        part: body
🐍 PoC Exploit & Verification Probe (Python 3) poc_cve-2025-54126.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2025-54126
# Target: bytecodealliance webassembly_micro_runtime | CVSS: 5.3 (MEDIUM)
# Educational & Security Audit Purpose Only

import requests
import sys

def verify_vulnerability(target_url):
    print(f"[*] Auditing {target_url} for CVE-2025-54126 (bytecodealliance webassembly_micro_runtime)...")
    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 bytecodealliance webassembly_micro_runtime 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-2025-54126.sh
# Recommended Remediation & Patching Commands for CVE-2025-54126
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install webassembly_micro_runtime 2>/dev/null || \
sudo dnf upgrade webassembly_micro_runtime 2>/dev/null || \
sudo yum update webassembly_micro_runtime

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

# 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-2025-54126 in bytecodealliance webassembly_micro_runtime?

Review vendor-specific security notices and update bytecodealliance webassembly_micro_runtime 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-2025-54126?

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-2025-54126?

CVE-2025-54126 is classified with a CVSS 3.1 Base Score of 5.3 (MEDIUM). Check the metric breakdown above for attack vector requirements.

Risk Snapshot
5.3
MEDIUM SEVERITY
CVE ID CVE-2025-54126
Weakness CWE-668
Vendor bytecodealliance
Product webassembly_micro_runtime
Published 2025-07-29
Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N