MEDIUM CVSS 4.7
Published: 2026-06-17

CVE-2026-44587

carrierwave_project carrierwave Security Advisory (CVE-2026-44587)
↗ Official NIST NVD Record
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CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2026-44587 impacting carrierwave_project carrierwave. Evaluated with CVSS Base Score of 4.7 (MEDIUM).

Original NVD Description

Source: NIST NVD
CarrierWave is a framework to upload files from Ruby applications. In versions prior to 2.2.7 and 3.1.3, the content_type_denylist check fails to escape regex metacharacters in string entries, causing the denylist to silently not match the content types it is intended to block. In lib/carrierwave/uploader/content_type_denylist.rb:57, denylist entries are interpolated directly into a regex without Regexp.quote or anchoring, so an entry such as image/svg+xml becomes the pattern /image\/svg+xml/, in which + is treated as a quantifier rather than a literal character and therefore never matches the real MIME type image/svg+xml. This is inconsistent with the allowlist implementation, which correctly applies both Regexp.quote and a \A anchor. Other content types containing regex metacharacters, such as application/xhtml+xml, are affected as well. As a result, any application that relies on content_type_denylist to block image/svg+xml, most commonly to prevent stored XSS, is silently unprotected. An attacker can upload an SVG file containing arbitrary JavaScript; if the application serves that SVG inline from its own origin, the script executes in the victim's browser, resulting in stored XSS. This issue has been fixed in versions 2.2.7 and 3.1.3.

📊 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
Required (UI:R)
User must click or open resource
Scope
Changed (S:C)
Impacts components beyond caller authority
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 carrierwave_project / carrierwave
Affected Versions *
Weakness Enumeration CWE-79

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-2026-44587 impacting carrierwave_project carrierwave.

⚡ Nuclei Detection Template (YAML) cve-2026-44587.yaml
id: cve-2026-44587

info:
  name: carrierwave_project carrierwave - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: medium
  description: |
    Automated signature & scanner for CVE-2026-44587 affecting carrierwave_project carrierwave.
    Evaluation: CarrierWave is a framework to upload files from Ruby applications. In versions prior to 2.2.7 and 3.1.3, the content_type_denylist check fails to esca...
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2026-44587
  classification:
    cvss-metrics: CVSS:3.1/CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:N/A:N
    cvss-score: 4.7
    cve-id: CVE-2026-44587
    cwe-id: CWE-79
  tags: cve,cve-2026-44587,carrierwave_project,carrierwave,medium

http:
  - method: GET
    path:
      - "{BaseURL}/"
      - "{BaseURL}/api/"
    matchers-condition: and
    matchers:
      - type: status
        status:
          - 200
      - type: word
        words:
          - "carrierwave"
        part: body
🐍 PoC Exploit & Verification Probe (Python 3) poc_cve-2026-44587.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2026-44587
# Target: carrierwave_project carrierwave | CVSS: 4.7 (MEDIUM)
# Educational & Security Audit Purpose Only

import requests
import sys

def verify_vulnerability(target_url):
    print(f"[*] Auditing {target_url} for CVE-2026-44587 (carrierwave_project carrierwave)...")
    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 carrierwave_project carrierwave 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-2026-44587.sh
# Recommended Remediation & Patching Commands for CVE-2026-44587
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install carrierwave 2>/dev/null || \
sudo dnf upgrade carrierwave 2>/dev/null || \
sudo yum update carrierwave

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

# 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-2026-44587 in carrierwave_project carrierwave?

Review vendor-specific security notices and update carrierwave_project carrierwave 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-2026-44587?

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-2026-44587?

CVE-2026-44587 is classified with a CVSS 3.1 Base Score of 4.7 (MEDIUM). Check the metric breakdown above for attack vector requirements.

Risk Snapshot
4.7
MEDIUM SEVERITY
CVE ID CVE-2026-44587
Weakness CWE-79
Vendor carrierwave_project
Product carrierwave
Published 2026-06-17
Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:N/A:N