External risk intelligence

Home Assistant Core Backup Restore Path Traversal Leads to Remote Code Execution

CVE advisorySeverity: CRITICAL (CVSS 9.3)

CVE-2026-64824

Home Assistant is often deployed as a self-hosted smart home controller. While many users expose these instances to the internet for remote access, the specific functionality affected involves backup restoration, which is typically an administrative task not directly exposed as a public-facing service.

Path Traversal

Halo Surface Signal: 3 out of 5 — possibly public-facing.

External exposure likelihood

Horizon Alert

Summary of the vulnerability and why it matters

A vulnerability in Home Assistant Core's backup-restore function allows an attacker to write files to arbitrary locations on the system, potentially leading to remote code execution, especially when the system runs with root privileges. This could allow attackers to compromise the smart home controller and any connected devices.

Backup restore flaw allows arbitrary file writes.
Critical remote code execution risk if exploited.
Confirm relevance and assess exposure to connected devices.

Attack Path

How an attacker could exploit the issue

An attacker with authenticated access could leverage a crafted backup file to traverse directories and write files to arbitrary locations on the system. This is made possible by a flaw in how the backup-restore function handles symbolic links within tar archives. If the Home Assistant process runs with root privileges, an attacker could overwrite critical Python files, leading to remote code execution.

Authenticated access is required.
Crafted backup archives with symlinks trigger the vulnerability.
Remote code execution via arbitrary file writes.

Live Threat

Current exploitation, exposure, and threat context

When supported by the advisory, an authenticated attacker with administrative privileges could write files to arbitrary filesystem locations. This could lead to the overwriting of critical system files or custom Python code when the official Docker image is used, potentially enabling remote code execution.

Arbitrary file write to system.
Crafted backup archive with symlink.
Remote code execution.

Operational Fix

Recommended remediation, mitigation, and detection steps

The Home Assistant platform team is likely responsible for addressing this vulnerability, given its impact on the core application. The first practical step is to identify all Home Assistant Core instances, assess their exposure and business criticality, and confirm the responsible owner for each. Subsequently, a remediation plan should be developed based on the identified risks.

Identify Home Assistant Core instances.
Verify backup restore function exposure.
Plan remediation based on risk.

Supplementary metadata

CVSS vector

Validate whether this threat affects your internet-facing exposure.

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Frequently asked questions

What is Home Assistant Core?

Home Assistant Core is an open-source automation platform designed to act as a centralized controller for smart home devices. It typically runs as a service on local hardware, managing integrations for lights, sensors, and appliances. In many common deployments, such as the official Docker container, it operates with elevated system privileges to interact directly with hardware and OS-level configurations.

What does CWE-22 mean for CVE-2026-64824?

CWE-22 refers to improper restriction of pathnames, commonly known as path traversal. In this CVE, the vulnerability exists because the backup-restore process fails to validate paths inside tar archive entries. An attacker can use symbolic links to escape the intended directory, tricking the software into writing files to protected system locations rather than the expected restoration folder.

How is this backup flaw triggered?

The issue is triggered when an attacker uploads a specially crafted backup file containing a symbolic link. It is not triggered by standard operations or casual use of the interface. The file must specifically leverage a SYMTYPE entry that points to an absolute path outside the extraction boundary. If the archive lacks these malicious symlinks, the restoration process behaves normally and does not execute the flaw.

Do I need to worry if my Home Assistant is internal?

Halo Surface Signal notes that while many users choose to expose instances to the internet for remote access, this vulnerability is tied to the backup restoration function. Since this is an administrative task, the risk depends on who can access your system's settings. If your instance is strictly internal, the attack surface is limited to users who have already gained authenticated access to your dashboard.

How should I respond to this threat?

Your first step is to identify all running Home Assistant Core instances in your environment. Prioritize updating to version 2026.6.0 or later, which addresses the flaw. Until you can update, strictly limit administrative access to the backup-restore feature and only perform restores from trusted, verified sources to prevent the introduction of malicious archive files.

References

Written by Nicholas Merritt

Nicholas Merritt is VP of Security Solutions at Halo Security. With more than 25 years across application security, vulnerability prioritization, and offensive security, he helps teams translate threat data into practical exposure validation and remediation focus. He authors Halo Threat Intelligence CVE advisories using Halo Surface Signal and H/A/L/O context to prioritize internet-facing risk.