CVE-2026-55850

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{"affected": [{"affectedData": [{"product": "element-web", "vendor": "element-hq", "versions": [{"status": "affected", "version": "< 1.12.22"}]}], "source": "security-advisories@github.com"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "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."}, {"lang": "es", "value": "Element Web es un cliente web de Matrix construido usando el SDK de React de Matrix. Antes de la versi\u00f3n 1.12.22, EmbeddedPage en apps/web/src/components/structures/EmbeddedPage.tsx renderiza contenido de la p\u00e1gina de inicio proporcionado por el homeserver a trav\u00e9s de dangerouslySetInnerHTML sin pasarlo por sanitizedHtmlNode. Un homeserver malicioso puede proporcionar HTML manipulado que Element Web renderiza en la p\u00e1gina de inicio; la pol\u00edtica de seguridad de contenido previene JavaScript pero no HTML de phishing. Este problema est\u00e1 solucionado en la versi\u00f3n 1.12.22."}], "id": "CVE-2026-55850", "lastModified": "2026-10-14T19:10:00.297", "metrics": {"cvssMetricV40": [{"cvssData": {"Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "LOW", "attackRequirements": "NONE", "attackVector": "NETWORK", "availabilityRequirement": "NOT_DEFINED", "baseScore": 5.3, "baseSeverity": "MEDIUM", "confidentialityRequirement": "NOT_DEFINED", "exploitMaturity": "NOT_DEFINED", "integrityRequirement": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "privilegesRequired": "NONE", "providerUrgency": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "userInteraction": "PASSIVE", "valueDensity": "NOT_DEFINED", "vectorString": "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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X", "version": "4.0", "vulnAvailabilityImpact": "NONE", "vulnConfidentialityImpact": "LOW", "vulnIntegrityImpact": "LOW", "vulnerabilityResponseEffort": "NOT_DEFINED"}, "source": "security-advisories@github.com", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-55850", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "role": "CISA Coordinator", "timestamp": "2026-08-21T19:54:43.766385Z", "version": "2.0.3"}}]}, "published": "2026-08-21T19:17:04.230", "references": [{"source": "security-advisories@github.com", "url": "https://github.com/element-hq/element-web/commit/7949980a7e3c7e397d7afe899ef1b0563c417b0e"}, {"source": "security-advisories@github.com", "url": "https://github.com/element-hq/element-web/releases/tag/v1.12.22"}, {"source": "security-advisories@github.com", "url": "https://github.com/element-hq/element-web/security/advisories/GHSA-wrcp-5v3v-3j6v"}, {"source": "security-advisories@github.com", "url": "https://www.machinespirits.com/advisory/563a17"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Deferred", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-79"}], "source": "security-advisories@github.com", "type": "Secondary"}]}

{}

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