Element Web is a Matrix web client built using the Matrix React SDK. Prior to 1.12.22, EmbeddedPage in apps/web/src/components/structures/EmbeddedPage.tsx renders homeserver-supplied homepage content through dangerouslySetInnerHTML without passing it through sanitizedHtmlNode. A malicious homeserver can provide crafted HTML that Element Web renders on the homepage; the content security policy prevents JavaScript but not phishing HTML. This issue is fixed in version 1.12.22.

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History

Fri, 21 Aug 2026 21:45:00 +0000

Type Values Removed Values Added
First Time appeared Element-hq
Element-hq element-web
Vendors & Products Element-hq
Element-hq element-web

Fri, 21 Aug 2026 20:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Fri, 21 Aug 2026 19:00:00 +0000

Type Values Removed Values Added
Description Element Web is a Matrix web client built using the Matrix React SDK. Prior to 1.12.22, EmbeddedPage in apps/web/src/components/structures/EmbeddedPage.tsx renders homeserver-supplied homepage content through dangerouslySetInnerHTML without passing it through sanitizedHtmlNode. A malicious homeserver can provide crafted HTML that Element Web renders on the homepage; the content security policy prevents JavaScript but not phishing HTML. This issue is fixed in version 1.12.22.
Title Element Web: A malicious homeserver can inject HTML in Element Web using its homepage
Weaknesses CWE-79
References
Metrics cvssV4_0

{'score': 5.3, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N'}


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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-08-21T19:54:55.604Z

Reserved: 2026-06-17T16:44:40.994Z

Link: CVE-2026-55850

cve-icon Vulnrichment

Updated: 2026-08-21T19:54:50.253Z

cve-icon NVD

Status : Received

Published: 2026-08-21T19:17:04.230

Modified: 2026-08-21T20:16:37.780

Link: CVE-2026-55850

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-08-21T21:15:00Z

Weaknesses