CVE-2026-55850

MEDIUMPre-NVD 5.35.3—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 5.3 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.3%, top 76% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
5.3EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 5.3Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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.

CVSS v3
5.3
EG Score
5.3(medium)
EG Risk
24(Track)
EG Risk 24/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity53% × 45%
Exploitation0% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
24%
KEV
Not listed

Published

August 21, 2026

Last Modified

August 21, 2026

Advisory Details (4)

Auto-updated Aug 21, 2026
Patch available. Sources: github_commit, github_release, github.
generic

CVE-2026-55850: Phishing via HTML Injection in Element Web

https://www.machinespirits.com/advisory/563a17
github_release Patch Available

v1.12.22

Patch available: element-hq/element-web v1.12.22

https://github.com/element-hq/element-web/releases/tag/v1.12.22
github_commit

commit 7949980a7e3c (element-hq/element-web)

Fix landed in element-hq/element-web commit 7949980a7e3c — awaiting tagged release

https://github.com/element-hq/element-web/commit/7949980a7e3c7e397d7afe899ef1b0563c417b0e
github Patch Available

A malicious homeserver can inject HTML in Element Web using its homepage · Advisory · element-hq/element-web · GitHub

https://github.com/element-hq/element-web/security/advisories/GHSA-wrcp-5v3v-3j6v

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 11× in last 7d / 17× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-08-30 01:22 UTCEPSS rescore
  2. 2026-08-29 14:21 UTCEG score recompute
  3. 2026-08-28 21:41 UTCEPSS rescore
  4. 2026-08-27 15:48 UTCEG score recompute
  5. 2026-08-27 14:25 UTCEPSS rescore
  6. 2026-08-26 16:31 UTCEG score recompute
  7. 2026-08-26 14:46 UTCEPSS rescore
  8. 2026-08-25 17:17 UTCEG score recompute
  9. 2026-08-25 13:49 UTCEPSS rescore
  10. 2026-08-24 18:04 UTCEG score recompute
  11. 2026-08-23 18:50 UTCEG score recompute
  12. 2026-08-23 00:19 UTCEPSS rescore
  13. 2026-08-21 20:23 UTCEG score recompute
  14. 2026-08-21 19:59 UTCEG score recompute
  15. 2026-08-21 19:21 UTCEG score recompute
  16. 2026-08-21 18:49 UTCEG score recompute
  17. 2026-08-21 18:49 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-55850?
CVE-2026-55850 is a medium vulnerability published on August 21, 2026. 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…
When was CVE-2026-55850 disclosed?
CVE-2026-55850 was first published in the National Vulnerability Database on August 21, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-55850 actively exploited?
CVE-2026-55850 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 76.2% of all scored CVEs.
What is the CVSS score of CVE-2026-55850?
CVE-2026-55850 has a CVSS v3 base score of 5.3 (NVD).
How do I remediate CVE-2026-55850?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-55850, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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