CVE-2026-64823 — Home Assistant Core < 2026.5.4 XSS via Shelly media_player.py thumb URI
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 …
Published: 2026-07-21 · CVSS: 2.1 · CVSS 4.0
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.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7