{"id":"CVE-2026-64823","aliases":["EUVD-2026-46280","GHSA-r3v5-j696-5grq"],"status":"published","title":"Home Assistant Core \u003c 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.","severity":{"version":"4.0","score":2.1,"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","level":"low","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.00296,"percentile":0.22403,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-79"],"published":"2026-07-21T15:16:03Z","modified":"2026-11-09T02:48:16Z","products":[{"vendor":"home-assistant","product":"home assistant core"}],"references":[{"url":"https://github.com/home-assistant/core/releases/tag/2026.5.4","tags":["release-notes","advisory"]},{"url":"https://github.com/home-assistant/core/pull/171585","tags":["issue-tracking","patch","fix"]},{"url":"https://github.com/home-assistant/core/commit/894a68acb678afc382fe5ea9002e61ab7f862011","tags":["patch","fix"]},{"url":"https://www.vulncheck.com/advisories/home-assistant-core-xss-via-shelly-media-player-py-thumb-uri","tags":["third-party-advisory","advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-64823","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-r3v5-j696-5grq"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64823.json","tags":["advisory"]},{"url":"https://github.com/home-assistant/core","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2026-64823","title":"Home Assistant Core \u003c 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.","status":"published","published":"2026-07-21T15:16:03.79Z","modified":"2026-11-08T14:07:59.946Z","cvss":[{"version":"4.0","score":2.1,"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","level":"low","assessor":"cna"},{"version":"3.1","score":4.7,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:N","level":"medium","assessor":"cna"}],"cwes":["CWE-79"],"updated_at":"2026-11-08T15:43:33.322657Z"}],"euvd":[{"id":"EUVD-2026-46280","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.","status":"published","published":"2026-07-21T15:16:03Z","modified":"2026-11-08T14:07:59Z","cvss":[{"version":"4.0","score":2.1,"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","level":"low"}],"updated_at":"2026-11-08T15:13:07.123106Z"}],"ghsa":[{"id":"GHSA-r3v5-j696-5grq","title":"Home Assistant Core before 2026.5.4 contains a cross-site scripting vulnerability in the Shelly...","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.","status":"published","published":"2026-07-21T18:31:01Z","modified":"2026-07-21T18:31:10Z","cvss":[{"version":"4.0","score":2.1,"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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"low"},{"version":"3.1","score":4.7,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:N","level":"medium"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T15:09:38.133598Z"}],"nvd":[{"id":"CVE-2026-64823","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.","status":"published","published":"2026-07-21T16:17:21.23Z","modified":"2026-10-24T19:10:00.127Z","cvss":[{"version":"4.0","score":2.1,"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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"low","assessor":"secondary"},{"version":"3.1","score":4.7,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:N","level":"medium","assessor":"secondary"}],"cwes":["CWE-79"],"updated_at":"2026-11-02T14:12:31.394335Z"}],"osv":[{"id":"CVE-2026-64823","title":"Home Assistant Core \u003c 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.","status":"published","published":"2026-07-21T15:16:03.79Z","modified":"2026-11-09T02:48:16.541024654Z","cvss":[{"version":"4.0","score":2.1,"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","level":"low"}],"cwes":["CWE-79"],"updated_at":"2026-11-09T03:15:52.404586Z"}]}}