CVE-2026-64823

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.

CVSS v3 4.7 MEDIUM

4.7^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 1.6 / Impact : 2.7

Attack Vector NETWORK

Attack Complexity HIGH

Privileges Required NONE

User Interaction REQUIRED

Confidentiality Impact LOW

Integrity Impact LOW

Availability Impact NONE

Scope CHANGED

References

Link	Resource
https://github.com/home-assistant/core/commit/894a68acb678afc382fe5ea9002e61ab7f862011
https://github.com/home-assistant/core/pull/171585
https://github.com/home-assistant/core/releases/tag/2026.5.4
https://www.vulncheck.com/advisories/home-assistant-core-xss-via-shelly-media-player-py-thumb-uri

Configurations

No configuration.

History

21 Jul 2026, 16:17

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-07-21 16:17

Updated : 2026-07-22 15:17

NVD link : CVE-2026-64823

Mitre link : CVE-2026-64823

CVE.ORG link : CVE-2026-64823

JSON object : View

Products Affected

No product.

CWE

CWE-79

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

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