Home Assistant: Cross-origin iframe access token exfiltration via WebView JS bridge callback injection
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||
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| home-assistant | core | affected |
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| Home Assistant | Companion app (iOS) | affected |
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| Home Assistant | Companion app (Android) | affected |
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No data.
No data.
| Vendor | Product | Versions | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Home-assistant | Companion App |
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| Home-assistant | Companion App |
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| Home-assistant | Core |
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No CVSS v4.0
No CVSS v3.0
No CVSS v2
This CVE is not in the KEV list.
Exploit prediction score: < 1% (0.149% probability within 30 days)
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Home-assistant
Home-assistant companion App Home-assistant core |
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| Vendors & Products |
Home-assistant
Home-assistant companion App Home-assistant core |
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
ssvc
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| Type | Values Removed | Values Added |
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| 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 |
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| References |
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| Metrics |
cvssV3_1
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