{"id":"CVE-2026-64823","state":"PUBLISHED","title":"Home Assistant Core < 2026.5.4 XSS via Shelly media_player.py thumb URI","description":"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.","publishedAt":"2026-07-21T15:16:03.790Z","updatedAt":"2026-07-22T14:12:16.922Z","severity":{"score":2.1,"label":"Low","version":"4.0","vector":"CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N","source":"VulnCheck"},"assigner":"VulnCheck","products":["home-assistant Home Assistant Core"],"affected":[{"vendor":"home-assistant","product":"Home Assistant Core","packageURL":"pkg:github/home-assistant/core","defaultStatus":"affected","versions":[{"version":"0","status":"affected","lessThan":"2026.5.4","versionType":"semver"}],"repo":"https://github.com/home-assistant/core"}],"references":["https://github.com/home-assistant/core/releases/tag/2026.5.4","https://github.com/home-assistant/core/pull/171585","https://github.com/home-assistant/core/commit/894a68acb678afc382fe5ea9002e61ab7f862011","https://www.vulncheck.com/advisories/home-assistant-core-xss-via-shelly-media-player-py-thumb-uri"],"weaknesses":["CWE-79"],"ingestedAt":"2026-10-29T20:12:41.951Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/64xxx/CVE-2026-64823.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-64823","state":"PUBLISHED","datePublished":"2026-07-21T15:16:03.790Z","dateUpdated":"2026-07-22T14:12:16.922Z","assignerShortName":"VulnCheck","assignerOrgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","dateReserved":"2026-07-20T18:27:48.160Z"},"containers":{"cna":{"title":"Home Assistant Core < 2026.5.4 XSS via Shelly media_player.py thumb URI","descriptions":[{"lang":"en","value":"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. 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