CVE-2026-44698 Home Assistant: Cross-origin iframe access token exfiltration via WebView JS bridge callback injection
Attackers can inject JavaScript via cross-origin iframes to steal user access tokens in Home Assistant mobile apps.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-44698?
CVE-2026-44698 is a high-severity cross-site scripting vulnerability in Home Assistant Companion app (Android), published on 29 May 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official 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.
Which versions are affected by CVE-2026-44698?
How do I fix CVE-2026-44698?
No fix has been published for CVE-2026-44698 yet. Limit exposure of the affected software until one is available.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-44698 being exploited?
There is no known exploitation of CVE-2026-44698 in the wild and no public exploit code.
Sources
Also known as GHSA-7jp2-p2fw-mgvf.