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Vulnerabilities

Vulnerability · CVE-2026-55850

Element Web is a Matrix web client built using the Matrix React SDK.

Published Aug 21, 2026 · catalog updated Oct 14, 2026 · Element Web is a

Check if you run it

No confirmed exploitation is on record for CVE-2026-55850. EPSS is 0.55%. Act only if a listed version of Element Web is a is installed.

Gaps on this record

  • The stored product name is a package slug. The name on this page is taken from the title (Element Web is a).
  • No version range is stored. A customer cannot check an installed version against this record.
  • No vendor fix or required action is stored. Compare the linked advisory before you change production.
Severity
Medium5.3
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.55%
Remediation
Advisory link
Affected products
See sources for product scope

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.

No affected version ranges are stored yet. Use the vendor advisory before you decide this record does not apply.

How to fix CVE-2026-55850

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2026-55850. EPSS is 0.55%. Act only if a listed version of Element Web is a is installed.

Which versions are affected?

Affected version ranges are not on this record. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

CWE-79: Cross-site Scripting (XSS). EPSS 0.55%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. Aug 21, 2026 · NIST NVD

    Detected

    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 prev

  2. Oct 14, 2026 · NIST NVD

    Updated

    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 prev

Sources

  • CVE.orgVulnerability recordCVE-2026-55850

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2026-55850

    30-day exploitation probability 0.5%

    first.org
  • NIST NVDVulnerability recordCVE-2026-55850

    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

    nvd.nist.gov

References

Freshness

Last verified in this catalog Oct 18, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.