CVE-2026-44698: CWE-94: Improper Control of Generation of Code ('Code Injection') in home-assistant core
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.
AI Analysis
Technical Summary
Home Assistant Companion apps for iOS and Android expose a JavaScript bridge (window.externalApp on Android and webkit.messageHandlers.getExternalAuth on iOS) to all frames including cross-origin iframes. Due to improper sanitization of the JavaScript callback identifier, a malicious cross-origin iframe can execute arbitrary JavaScript in the main-frame origin of the Home Assistant frontend and steal the user's access token. This is a code injection vulnerability categorized under CWE-94 and related weaknesses. The issue is resolved in versions 2026.4.1 for iOS and 2026.4.4 for Android.
Potential Impact
Successful exploitation allows a cross-origin iframe within the Companion app to execute arbitrary JavaScript in the context of the Home Assistant frontend's main frame. This leads to exfiltration of the signed-in user's access token, potentially enabling unauthorized access to the user's Home Assistant environment. The CVSS v3.1 score of 8.3 reflects high impact on confidentiality, integrity, and availability.
Mitigation Recommendations
A fix is available and has been released in Home Assistant Companion app versions 2026.4.1 for iOS and 2026.4.4 for Android. Users and administrators should update to these versions or later to remediate this vulnerability. Since this is a cloud service with companion apps, the vendor manages remediation for the cloud-hosted service, but client app updates are required to fully mitigate the issue.
CVE-2026-44698: CWE-94: Improper Control of Generation of Code ('Code Injection') in home-assistant core
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.
CVSS v3.1
Score 8.3high
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
Home Assistant Companion apps for iOS and Android expose a JavaScript bridge (window.externalApp on Android and webkit.messageHandlers.getExternalAuth on iOS) to all frames including cross-origin iframes. Due to improper sanitization of the JavaScript callback identifier, a malicious cross-origin iframe can execute arbitrary JavaScript in the main-frame origin of the Home Assistant frontend and steal the user's access token. This is a code injection vulnerability categorized under CWE-94 and related weaknesses. The issue is resolved in versions 2026.4.1 for iOS and 2026.4.4 for Android.
Potential Impact
Successful exploitation allows a cross-origin iframe within the Companion app to execute arbitrary JavaScript in the context of the Home Assistant frontend's main frame. This leads to exfiltration of the signed-in user's access token, potentially enabling unauthorized access to the user's Home Assistant environment. The CVSS v3.1 score of 8.3 reflects high impact on confidentiality, integrity, and availability.
Mitigation Recommendations
A fix is available and has been released in Home Assistant Companion app versions 2026.4.1 for iOS and 2026.4.4 for Android. Users and administrators should update to these versions or later to remediate this vulnerability. Since this is a cloud service with companion apps, the vendor manages remediation for the cloud-hosted service, but client app updates are required to fully mitigate the issue.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-05-07T17:07:09.316Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
- Is Cloud Service
- true
Threat ID: 6a199936e29bf47b50eaf3db
Added to database: 5/29/2026, 1:48:38 PM
Last enriched: 5/29/2026, 2:04:29 PM
Last updated: 5/31/2026, 4:53:42 AM
Views: 13
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