CVE-2026-64825

critical

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.

References

https://www.vulncheck.com/advisories/home-assistant-core-path-traversal-file-write-via-backup-upload

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

Details

Source: Mitre, NVD

Published: 2026-07-21

Updated: 2026-07-21

Risk Information

CVSS v2

Base Score: 8.5

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:C/A:P

Severity: High

CVSS v3

Base Score: 9.3

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:L

Severity: Critical

CVSS v4

Base Score: 9

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

Severity: Critical

EPSS

EPSS: 0.00482