MEDIUM CVSS 6.3
Published: 2026-06-16

CVE-2026-10635

zephyrproject zephyr Security Advisory (CVE-2026-10635)
↗ Official NIST NVD Record
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CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2026-10635 impacting zephyrproject zephyr. Evaluated with CVSS Base Score of 6.3 (MEDIUM).

Original NVD Description

Source: NIST NVD
On Xtensa targets with CONFIG_USERSPACE and CONFIG_XTENSA_MMU, the page-table code (arch/xtensa/core/ptables.c) maintains a global list, xtensa_domain_list, of active memory domains using a list node embedded inside the caller-owned struct k_mem_domain. When a domain is destroyed via k_mem_domain_deinit() -> arch_mem_domain_deinit(), the page tables are torn down and domain->arch.ptables is set to NULL, but the domain's node was not removed from xtensa_domain_list. The freed/deinitialized domain therefore remained linked into the global list as a dangling pointer into caller-owned storage that may then be freed or reused. Any subsequent arch_mem_map()/arch_mem_unmap() operation (widely invoked by kernel memory-mapping and demand-paging code) traverses the stale node and dereferences domain->ptables: at minimum a NULL pointer dereference causing a fatal MMU exception (denial of service), and if the k_mem_domain storage has been freed or reused, a use-after-free in which a stale/controlled ptables value is dereferenced and written through during the page-table walk (l2_page_table_map writes l1_table[...] and l2_table[...], and xtensa_mmu_compute_domain_regs writes into the domain struct and the L1 table), yielding page-table memory corruption that can undermine userspace isolation. The vulnerable path is reachable only from privileged kernel/supervisor code (k_mem_domain_deinit is not a syscall), not directly from unprivileged user threads or remotely. Affected: Zephyr v4.4.0 (the Xtensa memory-domain de-initialization feature was introduced in commit 3032b58f52d and first shipped in v4.4.0); fixed on main by adding sys_slist_find_and_remove() in arch_mem_domain_deinit(). The Xtensa MPU path is unaffected.

📊 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
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
Low (C:L)
Partial information leakage
Integrity
High (I:H)
Total modification of target system
Availability
High (A:H)
Total denial of service or shutdown

🎯 Affected Versions Matrix

Affected Product zephyrproject / zephyr
Affected Versions 4.4.0
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-2026-10635 impacting zephyrproject zephyr.

⚡ Nuclei Detection Template (YAML) cve-2026-10635.yaml
id: cve-2026-10635

info:
  name: zephyrproject zephyr - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: medium
  description: |
    Automated signature & scanner for CVE-2026-10635 affecting zephyrproject zephyr.
    Evaluation: On Xtensa targets with CONFIG_USERSPACE and CONFIG_XTENSA_MMU, the page-table code (arch/xtensa/core/ptables.c) maintains a global list, xtensa_domain...
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2026-10635
  classification:
    cvss-metrics: CVSS:3.1/CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:L/I:H/A:H
    cvss-score: 6.3
    cve-id: CVE-2026-10635
    cwe-id: CWE-416
  tags: cve,cve-2026-10635,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-2026-10635.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2026-10635
# Target: zephyrproject zephyr | CVSS: 6.3 (MEDIUM)
# Educational & Security Audit Purpose Only

import requests
import sys

def verify_vulnerability(target_url):
    print(f"[*] Auditing {target_url} for CVE-2026-10635 (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 (4.4.0).")
        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-2026-10635.sh
# Recommended Remediation & Patching Commands for CVE-2026-10635
# 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-2026-10635 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-2026-10635?

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-2026-10635?

CVE-2026-10635 is classified with a CVSS 3.1 Base Score of 6.3 (MEDIUM). Check the metric breakdown above for attack vector requirements.

Risk Snapshot
6.3
MEDIUM SEVERITY
CVE ID CVE-2026-10635
Weakness CWE-416
Vendor zephyrproject
Product zephyr
Published 2026-06-16
Vector CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:L/I:H/A:H