Home Assistant is open source home automation software that puts local control and privacy first. Prior to 2026.4.1 for iOS and 2026.4.4 for Android, he Home Assistant Companion apps for Android and iOS expose a JavaScript bridge to the in-app WebView window.externalApp on Android and webkit.messageHandlers.getExternalAuth (alongside revokeExternalAuth and externalBus) on iOS. Two flaws expose the bridge to all frames (including cross-origin iframes) and unsanitized interpolation of the JavaScript callback identifier allows a cross-origin iframe rendered inside the Companion app to execute arbitrary JavaScript in the Home Assistant frontend's main-frame origin and exfiltrate the signed-in user's access token. This vulnerability is fixed in 2026.4.1 for iOS and 2026.4.4 for Android.
History

Fri, 29 May 2026 16:00:00 +0000

Type Values Removed Values Added
First Time appeared Home-assistant
Home-assistant companion App
Home-assistant core
Vendors & Products Home-assistant
Home-assistant companion App
Home-assistant core

Fri, 29 May 2026 14:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}


Fri, 29 May 2026 13:45:00 +0000

Type Values Removed Values Added
Description Home Assistant is open source home automation software that puts local control and privacy first. Prior to 2026.4.1 for iOS and 2026.4.4 for Android, he Home Assistant Companion apps for Android and iOS expose a JavaScript bridge to the in-app WebView window.externalApp on Android and webkit.messageHandlers.getExternalAuth (alongside revokeExternalAuth and externalBus) on iOS. Two flaws expose the bridge to all frames (including cross-origin iframes) and unsanitized interpolation of the JavaScript callback identifier allows a cross-origin iframe rendered inside the Companion app to execute arbitrary JavaScript in the Home Assistant frontend's main-frame origin and exfiltrate the signed-in user's access token. This vulnerability is fixed in 2026.4.1 for iOS and 2026.4.4 for Android.
Title Home Assistant: Cross-origin iframe access token exfiltration via WebView JS bridge callback injection
Weaknesses CWE-346
CWE-749
CWE-94
CWE-940
References
Metrics cvssV3_1

{'score': 8.3, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:H'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-05-29T13:58:53.347Z

Reserved: 2026-05-07T17:07:09.316Z

Link: CVE-2026-44698

cve-icon Vulnrichment

Updated: 2026-05-29T13:58:49.847Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-05-29T14:16:28.823

Modified: 2026-05-29T16:25:57.843

Link: CVE-2026-44698

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-05-29T15:46:28Z