PT-2026-61960 · Home Assistant · Home Assistant Core

Harish Kolla · CVE-2026-64823 · Published 2026-07-21 · Updated 2026-07-21

NVD

CVSS v3.1

4.7

Medium

Base vector

AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:N

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.

Fix

XSS

Weakness Enumeration

CWE-79

Related Identifiers

CVE-2026-64823

Affected Products

Home Assistant Core

References · 5

• https://github.com/home-assistant/core/commit/894a68acb678afc382fe5ea9002e61ab7f862011 · Patch
• https://nvd.nist.gov/vuln/detail/CVE-2026-64823 · Security Note
• https://github.com/home-assistant/core/releases/tag/2026.5.4 · Note
• https://github.com/home-assistant/core/pull/171585 · Note
• https://vulncheck.com/advisories/home-assistant-core-xss-via-shelly-media-player-py-thumb-uri · Note