CVE-2026-55644: CWE-20: Improper Input Validation in element-hq element-x-ios
Description
Element X iOS versions prior to 26.05.0 contain an improper input validation vulnerability in the handling of io.element.call:// URLs. This flaw allows an attacker to bypass the URL allowlist when parsing these URLs, potentially loading attacker-controlled content inside the call screen's WKWebView. If the user has previously granted microphone and camera permissions to Element X iOS, the malicious content can access these device features. The issue has been fixed in version 26.05.0.
CVSS v4.0
Score 5.1medium
Affected software
element-hq
element-x-ios
pkg:github/element-hq/element-x-iosRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
Element X iOS before version 26.05.0 fails to properly validate input URLs with the io.element.call:// scheme, allowing an attacker to craft a malicious URL that loads attacker-controlled origins inside the call screen's WKWebView. This WebView inherits microphone and camera permissions granted to the app, enabling unauthorized access to these device features if the user has already granted permissions. The vulnerability is classified as CWE-20 (Improper Input Validation) and has a CVSS 4.0 base score of 5.1 (medium severity). The issue is patched in version 26.05.0.
Potential Impact
An attacker who can trick a user into opening a maliciously crafted io.element.call:// URL can cause the app to load attacker-controlled content with access to the device's microphone and camera, assuming the user previously granted these permissions to Element X iOS. This could lead to unauthorized audio and video capture. There is no indication of required privileges or user interaction beyond opening the URL. No known exploits are reported in the wild.
Mitigation Recommendations
Upgrade Element X iOS to version 26.05.0 or later, where this vulnerability is patched. Users should avoid opening io.element.call:// URLs from untrusted sources until the update is applied.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-06-16T23:52:12.058Z
- Cvss Version
- 4.0
- State
- PUBLISHED
Threat ID: 6ad65b9b2cdf04f6567c0f9e
Added to database: 10/19/2026, 18:04:11 UTC
Last enriched: 10/19/2026, 18:18:24 UTC
Last updated: 10/19/2026, 18:19:13 UTC
Views: 4
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