MEDIUM CVSS 6.2
Published: 2026-07-09

CVE-2026-39245

decompress_project decompress Security Advisory (CVE-2026-39245)
↗ Official NIST NVD Record
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CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2026-39245 impacting decompress_project decompress. Evaluated with CVSS Base Score of 6.2 (MEDIUM).

Original NVD Description

Source: NIST NVD
decompress before 4.2.2 contains an improper path containment check that enables directory traversal and arbitrary file write. The safeMakeDir function (index.js line 29) and the extraction path validation (index.js line 106) use String.indexOf() to verify the resolved path is within the output directory: realDestinationDir.indexOf(realOutputPath) !== 0. This check is flawed because it does not enforce a path separator boundary. For example, "/tmp/app_config".indexOf("/tmp/app") returns 0, incorrectly passing the check even though /tmp/app_config is outside /tmp/app. Combined with the unvalidated symlink creation in the same package, an attacker can write arbitrary files to directories adjacent to the extraction target. This is a bypass of the fix for CVE-2020-12265. The correct check requires appending a path separator: realParentPath.indexOf(realOutputPath + path.sep) !== 0.

📊 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
None (PR:N)
Unauthenticated execution
User Interaction
None (UI:N)
Zero human interaction required
Scope
Unchanged (S:U)
Confined to same security context
Confidentiality
None (C:N)
No data confidentiality impact
Integrity
High (I:H)
Total modification of target system
Availability
None (A:N)
No system availability impact

🎯 Affected Versions Matrix

Affected Product decompress_project / decompress
Affected Versions *
Weakness Enumeration CWE-22

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-2026-39245 impacting decompress_project decompress.

⚡ Nuclei Detection Template (YAML) cve-2026-39245.yaml
id: cve-2026-39245

info:
  name: decompress_project decompress - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: medium
  description: |
    Automated signature & scanner for CVE-2026-39245 affecting decompress_project decompress.
    Evaluation: decompress before 4.2.2 contains an improper path containment check that enables directory traversal and arbitrary file write. The safeMakeDir functio...
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2026-39245
  classification:
    cvss-metrics: CVSS:3.1/CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
    cvss-score: 6.2
    cve-id: CVE-2026-39245
    cwe-id: CWE-22
  tags: cve,cve-2026-39245,decompress_project,decompress,medium

http:
  - method: GET
    path:
      - "{BaseURL}/"
      - "{BaseURL}/api/"
    matchers-condition: and
    matchers:
      - type: status
        status:
          - 200
      - type: word
        words:
          - "decompress"
        part: body
🐍 PoC Exploit & Verification Probe (Python 3) poc_cve-2026-39245.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2026-39245
# Target: decompress_project decompress | CVSS: 6.2 (MEDIUM)
# Educational & Security Audit Purpose Only

import requests
import sys

def verify_vulnerability(target_url):
    print(f"[*] Auditing {target_url} for CVE-2026-39245 (decompress_project decompress)...")
    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 decompress_project decompress 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-2026-39245.sh
# Recommended Remediation & Patching Commands for CVE-2026-39245
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install decompress 2>/dev/null || \
sudo dnf upgrade decompress 2>/dev/null || \
sudo yum update decompress

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

# 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-2026-39245 in decompress_project decompress?

Review vendor-specific security notices and update decompress_project decompress 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-2026-39245?

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-2026-39245?

CVE-2026-39245 is classified with a CVSS 3.1 Base Score of 6.2 (MEDIUM). Check the metric breakdown above for attack vector requirements.

Risk Snapshot
6.2
MEDIUM SEVERITY
CVE ID CVE-2026-39245
Weakness CWE-22
Vendor decompress_project
Product decompress
Published 2026-07-09
Vector CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N