MEDIUM CVSS 4.8
Published: 2026-06-15

CVE-2026-10634

zephyrproject zephyr Security Advisory (CVE-2026-10634)
↗ Official NIST NVD Record
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CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2026-10634 impacting zephyrproject zephyr. Evaluated with CVSS Base Score of 4.8 (MEDIUM).

Original NVD Description

Source: NIST NVD
Zephyr's native TCP stack iterates the global connection list in net_tcp_foreach() (subsys/net/ip/tcp.c) using the SYS_SLIST_FOR_EACH_CONTAINER_SAFE macro, which caches a pointer to the next list node. Prior to this fix the function released tcp_lock while invoking the per-connection callback and re-acquired it afterwards. During that window a concurrent tcp_conn_release(), running on the dedicated TCP work-queue thread when a connection's reference count drops to zero (e.g. a remote peer closing or resetting the connection), can remove and k_mem_slab_free() the cached next connection. When the iterator advances it dereferences the freed (and possibly reallocated) slab memory — a use-after-free that can crash the system (denial of service) and, if the slot has been reused, cause the callback to operate on an attacker-influenced object (potential information disclosure or further fault). net_tcp_foreach() is reached in production via the net conn network shell command and via net_tcp_close_all_for_iface() on interface-down; the freeing side is driven by ordinary TCP traffic. The fix moves the connection/context teardown in tcp_conn_release() inside the tcp_lock critical section and keeps tcp_lock held across the callback in net_tcp_foreach(). The defect was introduced with the modern (TCP2) stack in 2020 and affects releases up to and including v4.4.0.

📊 CVSS v3.1 Metric Breakdown

Attack Vector
Adjacent (AV:A)
Requires shared subnet / local network access
Attack Complexity
High (AC:H)
Depends on race conditions or environment
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 zephyrproject / zephyr
Affected Versions *
Weakness Enumeration CWE-416

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-2026-10634 impacting zephyrproject zephyr.

⚡ Nuclei Detection Template (YAML) cve-2026-10634.yaml
id: cve-2026-10634

info:
  name: zephyrproject zephyr - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: medium
  description: |
    Automated signature & scanner for CVE-2026-10634 affecting zephyrproject zephyr.
    Evaluation: Zephyr's native TCP stack iterates the global connection list in net_tcp_foreach() (subsys/net/ip/tcp.c) using the SYS_SLIST_FOR_EACH_CONTAINER_S...
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2026-10634
  classification:
    cvss-metrics: CVSS:3.1/CVSS:3.1/AV:A/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
    cvss-score: 4.8
    cve-id: CVE-2026-10634
    cwe-id: CWE-416
  tags: cve,cve-2026-10634,zephyrproject,zephyr,medium

http:
  - method: GET
    path:
      - "{BaseURL}/"
      - "{BaseURL}/api/"
    matchers-condition: and
    matchers:
      - type: status
        status:
          - 200
      - type: word
        words:
          - "zephyr"
        part: body
🐍 PoC Exploit & Verification Probe (Python 3) poc_cve-2026-10634.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2026-10634
# Target: zephyrproject zephyr | CVSS: 4.8 (MEDIUM)
# Educational & Security Audit Purpose Only

import requests
import sys

def verify_vulnerability(target_url):
    print(f"[*] Auditing {target_url} for CVE-2026-10634 (zephyrproject zephyr)...")
    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 zephyrproject zephyr 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-2026-10634.sh
# Recommended Remediation & Patching Commands for CVE-2026-10634
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install zephyr 2>/dev/null || \
sudo dnf upgrade zephyr 2>/dev/null || \
sudo yum update zephyr

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

# 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.

🔗 Verified Technical References

❓ Frequently Asked Questions (FAQ) & Remediation Guide

How do I fix CVE-2026-10634 in zephyrproject zephyr?

Review vendor-specific security notices and update zephyrproject zephyr 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-2026-10634?

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-2026-10634?

CVE-2026-10634 is classified with a CVSS 3.1 Base Score of 4.8 (MEDIUM). Check the metric breakdown above for attack vector requirements.

Risk Snapshot
4.8
MEDIUM SEVERITY
CVE ID CVE-2026-10634
Weakness CWE-416
Vendor zephyrproject
Product zephyr
Published 2026-06-15
Vector CVSS:3.1/AV:A/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H