CVE-2026-44698
Home Assistant: Cross-origin iframe access token exfiltration via WebView JS bridge callback injection
- Published
- Updated
- Reserved
- Assigned by
- GitHub_M
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.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 3.1 | High8.3 | CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:H |
| NVDNVD · Awaiting Analysis | 3.1 | High8.3 | CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 0.14% · top 97% of all CVEs (6 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: total
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 8.3.
Weakness
- CWE-94: Improper Control of Generation of Code ('Code Injection') (opens in a new tab)All about CWE-94 and its CVEs
- CWE-346: Origin Validation Error (opens in a new tab)All about CWE-346 and its CVEs
- CWE-749: Exposed Dangerous Method or Function (opens in a new tab)All about CWE-749 and its CVEs
- CWE-940: Improper Verification of Source of a Communication Channel (opens in a new tab)All about CWE-940 and its CVEs
Affected products
- affected < 2026.4.4
Home Assistant · Companion app (iOS)
- affected < 2026.4.1
Home Assistant · Companion app (Android)
- affected < 2026.4.4
References (1)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2026-44698)Record last updated .