CVE-2026-64823
Published:July 21, 2026
Updated:August 04, 2026
Home Assistant Core before 2026.5.4 contains a cross-site scripting vulnerability in the Shelly integration's async_get_media_image() method that allows attackers controlling a Shelly device's thumb field to serve arbitrary HTML content by supplying a data URI with a text/html content type without validation against an image-only allowlist. Attackers can cause the media player proxy endpoint to serve attacker-controlled bytes with Content-Type text/html in the Home Assistant web origin, enabling theft of session tokens from local storage and authenticated calls to sensitive service endpoints including lock, alarm, and cover controls.
Affected Packages
homeassistant (CONDA):
Affected version(s) >=2021.9.7 <2026.5.4Fix Suggestion:
Update to version 2026.5.4https://github.com/home-assistant/core.git (GITHUB):
Affected version(s) >=Last-Python2-release <2026.5.4Fix Suggestion:
Update to version 2026.5.4homeassistant (PYTHON):
Affected version(s) >=0.7.0rc1 <2026.5.4Fix Suggestion:
Update to version 2026.5.4Related Resources (7)
Do you need more information?
Contact UsCVSS v4
Base Score:
2.1
Attack Vector
NETWORK
Attack Complexity
HIGH
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
ACTIVE
Vulnerable System Confidentiality
NONE
Vulnerable System Integrity
NONE
Vulnerable System Availability
NONE
Subsequent System Confidentiality
LOW
Subsequent System Integrity
LOW
Subsequent System Availability
NONE
CVSS v3
Base Score:
4.7
Attack Vector
NETWORK
Attack Complexity
HIGH
Privileges Required
NONE
User Interaction
REQUIRED
Scope
CHANGED
Confidentiality
LOW
Integrity
LOW
Availability
NONE
Weakness Type (CWE)
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
EPSS
Base Score:
0.18