Medium severity · published Aug 21, 2026
CVE-2026-55850
Element Web: A malicious homeserver can inject HTML in Element Web using its homepage
5.3
CVSS
0.5%
EPSS
No
On KEV
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.
Exploitation
Is it being used?
Exploit prediction (EPSS)0.5% · higher than 46% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
EL
element-web · element-hq
< 1.12.22 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-55850
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-55850
github.com
https://github.com/element-hq/element-web/commit/7949980a7e3c7e397d7afe899ef1b0563c417b0e
github.com
https://github.com/element-hq/element-web/releases/tag/v1.12.22
github.com
https://github.com/element-hq/element-web/security/advisories/GHSA-wrcp-5v3v-3j6v
www.machinespirits.com
https://www.machinespirits.com/advisory/563a17
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