CVE-2026-55850 element-hq CVE debrief

Who should care

Organizations and users of Element Web, particularly those with high-security requirements, should be aware of this vulnerability and take steps to mitigate potential risks. This includes updating to version 1.12.22 or later, reviewing and monitoring homeserver-supplied content for potential phishing attempts, and implementing additional security measures to detect and prevent phishing attacks. Security teams and vulnerability management teams should prioritize this update and review their deployments for potential exposure.

Technical summary

The EmbeddedPage component in Element Web, prior to version 1.12.22, rendered homeserver-supplied content without proper sanitization, allowing for potential phishing attacks via crafted HTML. This issue was fixed in version 1.12.22. The vulnerability has a CVSS score of 5.3 and a severity of MEDIUM. Users of Element Web should update to version 1.12.22 or later to address potential phishing risks.

Defensive priority

Organizations using Element Web should prioritize updating to version 1.12.22 or later to address potential phishing risks.

Recommended defensive actions

• Update Element Web to version 1.12.22 or later
• Review and monitor homeserver-supplied content for potential phishing attempts
• Implement additional security measures to detect and prevent phishing attacks
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up.
• Review the supplied official advisory or CVE record to validate affected scope, severity, and vendor guidance.
• Plan vendor-supported updates or mitigations through normal change control where exposure is confirmed.
• Check relevant monitoring, detection, and logs for exposed assets that need extra review.

Evidence notes

The CVE record indicates that Element Web, a Matrix web client, had a vulnerability prior to version 1.12.22. The issue involved EmbeddedPage rendering homeserver-supplied content without proper sanitization, allowing for potential phishing attacks. Organizations should verify their deployments, review official advisories, and consider compensating controls. The vulnerability was fixed in version 1.12.22, and users should update to this version or later. Additionally, users should be cautious of potential phishing attempts through crafted HTML and monitor homeserver-supplied content.

Official resources