MEDIUM CVSS 5.9
Published: 2026-02-19

CVE-2026-26189

aquasec trivy_action Security Advisory (CVE-2026-26189)
↗ Official NIST NVD Record
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CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2026-26189 impacting aquasec trivy_action. Evaluated with CVSS Base Score of 5.9 (MEDIUM).

Original NVD Description

Source: NIST NVD
Trivy Action runs Trivy as GitHub action to scan a Docker container image for vulnerabilities. A command injection vulnerability exists in `aquasecurity/trivy-action` versions 0.31.0 through 0.33.1 due to improper handling of action inputs when exporting environment variables. The action writes `export VAR=<input>` lines to `trivy_envs.txt` based on user-supplied inputs and subsequently sources this file in `entrypoint.sh`. Because input values are written without appropriate shell escaping, attacker-controlled input containing shell metacharacters (e.g., `$(...)`, backticks, or other command substitution syntax) may be evaluated during the sourcing process. This can result in arbitrary command execution within the GitHub Actions runner context. Version 0.34.0 contains a patch for this issue. The vulnerability is exploitable when a consuming workflow passes attacker-controlled data into any action input that is written to `trivy_envs.txt`. Access to user input is required by the malicious actor. Workflows that do not pass attacker-controlled data into `trivy-action` inputs, workflows that upgrade to a patched version that properly escapes shell values or eliminates the `source ./trivy_envs.txt` pattern, and workflows where user input is not accessible are not affected.

📊 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
High (PR:H)
Administrative credentials 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
None (A:N)
No system availability impact

🎯 Affected Versions Matrix

Affected Product aquasec / trivy_action
Affected Versions *
Weakness Enumeration CWE-78

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-2026-26189 impacting aquasec trivy_action.

⚡ Nuclei Detection Template (YAML) cve-2026-26189.yaml
id: cve-2026-26189

info:
  name: aquasec trivy_action - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: medium
  description: |
    Automated signature & scanner for CVE-2026-26189 affecting aquasec trivy_action.
    Evaluation: Trivy Action runs Trivy as GitHub action to scan a Docker container image for vulnerabilities. A command injection vulnerability exists in `aquasecuri...
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2026-26189
  classification:
    cvss-metrics: CVSS:3.1/CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:N
    cvss-score: 5.9
    cve-id: CVE-2026-26189
    cwe-id: CWE-78
  tags: cve,cve-2026-26189,aquasec,trivy_action,medium

http:
  - method: GET
    path:
      - "{BaseURL}/"
      - "{BaseURL}/api/"
    matchers-condition: and
    matchers:
      - type: status
        status:
          - 200
      - type: word
        words:
          - "trivy_action"
        part: body
🐍 PoC Exploit & Verification Probe (Python 3) poc_cve-2026-26189.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2026-26189
# Target: aquasec trivy_action | CVSS: 5.9 (MEDIUM)
# Educational & Security Audit Purpose Only

import requests
import sys

def verify_vulnerability(target_url):
    print(f"[*] Auditing {target_url} for CVE-2026-26189 (aquasec trivy_action)...")
    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 aquasec trivy_action 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-2026-26189.sh
# Recommended Remediation & Patching Commands for CVE-2026-26189
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install trivy_action 2>/dev/null || \
sudo dnf upgrade trivy_action 2>/dev/null || \
sudo yum update trivy_action

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

# 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-2026-26189 in aquasec trivy_action?

Review vendor-specific security notices and update aquasec trivy_action 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-2026-26189?

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-2026-26189?

CVE-2026-26189 is classified with a CVSS 3.1 Base Score of 5.9 (MEDIUM). Check the metric breakdown above for attack vector requirements.

Risk Snapshot
5.9
MEDIUM SEVERITY
CVE ID CVE-2026-26189
Weakness CWE-78
Vendor aquasec
Product trivy_action
Published 2026-02-19
Vector CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:N