MEDIUM CVSS 6.5
Published: 2026-03-20

CVE-2026-32937

free5gc free5gc Security Advisory (CVE-2026-32937)
↗ Official NIST NVD Record
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CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2026-32937 impacting free5gc free5gc. Evaluated with CVSS Base Score of 6.5 (MEDIUM).

Original NVD Description

Source: NIST NVD
free5GC is an open source 5G core network. free5GC CHF prior to version 1.2.2 has an out-of-bounds slice access vulnerability in the CHF `nchf-convergedcharging` service. A valid authenticated request to PUT `/nchf-convergedcharging/v3/recharging/:ueId?ratingGroup=...` can trigger a server-side panic in `github.com/free5gc/chf/internal/sbi.(*Server).RechargePut(...)` due to an out-of-range slice access. In the reported runtime, Gin recovery converts the panic into HTTP 500, but the recharge path remains remotely panic-triggerable and can be abused repeatedly to degrade recharge functionality and flood logs. In deployments without equivalent recovery handling, this panic may cause more severe service disruption. free5GC CHF patches the issue. Some workarounds are available: Restrict access to the `nchf-convergedcharging` recharge endpoint to strictly trusted NF callers only; apply rate limiting or network ACLs in front of the CHF SBI interface to reduce repeated panic-trigger attempts; if the recharge API is not required, temporarily disable or block external reachability to this route; and/or ensure panic recovery, monitoring, and alerting are enabled.

📊 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
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
None (C:N)
No data confidentiality impact
Integrity
None (I:N)
No system modification impact
Availability
High (A:H)
Total denial of service or shutdown

🎯 Affected Versions Matrix

Affected Product free5gc / free5gc
Affected Versions *
Weakness Enumeration CWE-129

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-2026-32937 impacting free5gc free5gc.

⚡ Nuclei Detection Template (YAML) cve-2026-32937.yaml
id: cve-2026-32937

info:
  name: free5gc free5gc - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: medium
  description: |
    Automated signature & scanner for CVE-2026-32937 affecting free5gc free5gc.
    Evaluation: free5GC is an open source 5G core network. free5GC CHF prior to version 1.2.2 has an out-of-bounds slice access vulnerability in the CHF `nchf-converg...
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2026-32937
  classification:
    cvss-metrics: CVSS:3.1/CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
    cvss-score: 6.5
    cve-id: CVE-2026-32937
    cwe-id: CWE-129
  tags: cve,cve-2026-32937,free5gc,free5gc,medium

http:
  - method: GET
    path:
      - "{BaseURL}/"
      - "{BaseURL}/api/"
    matchers-condition: and
    matchers:
      - type: status
        status:
          - 200
      - type: word
        words:
          - "free5gc"
        part: body
🐍 PoC Exploit & Verification Probe (Python 3) poc_cve-2026-32937.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2026-32937
# Target: free5gc free5gc | CVSS: 6.5 (MEDIUM)
# Educational & Security Audit Purpose Only

import requests
import sys

def verify_vulnerability(target_url):
    print(f"[*] Auditing {target_url} for CVE-2026-32937 (free5gc free5gc)...")
    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 free5gc free5gc 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-2026-32937.sh
# Recommended Remediation & Patching Commands for CVE-2026-32937
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install free5gc 2>/dev/null || \
sudo dnf upgrade free5gc 2>/dev/null || \
sudo yum update free5gc

# 2. Inspect installed package versions for vulnerable scope:
dpkg -l | grep -i free5gc 2>/dev/null || rpm -qa | grep -i free5gc

# 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-2026-32937 in free5gc free5gc?

Review vendor-specific security notices and update free5gc free5gc 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-2026-32937?

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-2026-32937?

CVE-2026-32937 is classified with a CVSS 3.1 Base Score of 6.5 (MEDIUM). Check the metric breakdown above for attack vector requirements.

Risk Snapshot
6.5
MEDIUM SEVERITY
CVE ID CVE-2026-32937
Weakness CWE-129
Vendor free5gc
Product free5gc
Published 2026-03-20
Vector CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H