{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-54521", "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "state": "PUBLISHED", "assignerShortName": "GitHub_M", "dateReserved": "2026-06-15T18:40:01.651Z", "datePublished": "2026-09-17T20:17:47.341Z", "dateUpdated": "2026-09-18T20:08:14.389Z"}, "containers": {"cna": {"title": "FairEmail: Cross-site scripting (XSS) in AMP message rendering (ActivityAMP)", "problemTypes": [{"descriptions": [{"cweId": "CWE-79", "lang": "en", "description": "CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')", "type": "CWE"}]}], "metrics": [{"cvssV3_1": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 6.1, "baseSeverity": "MEDIUM", "confidentialityImpact": "LOW", "integrityImpact": "LOW", "privilegesRequired": "NONE", "scope": "CHANGED", "userInteraction": "REQUIRED", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N", "version": "3.1"}}], "references": [{"name": "https://github.com/M66B/FairEmail/security/advisories/GHSA-r8ff-qr7g-pvw6", "tags": ["x_refsource_CONFIRM"], "url": "https://github.com/M66B/FairEmail/security/advisories/GHSA-r8ff-qr7g-pvw6"}, {"name": "https://github.com/M66B/FairEmail/commit/fb37bbfabf5e75d08f0cfa6ce9b84469d62a20a0", "tags": ["x_refsource_MISC"], "url": "https://github.com/M66B/FairEmail/commit/fb37bbfabf5e75d08f0cfa6ce9b84469d62a20a0"}, {"name": "https://github.com/M66B/FairEmail/releases/tag/1.2319", "tags": ["x_refsource_MISC"], "url": "https://github.com/M66B/FairEmail/releases/tag/1.2319"}], "affected": [{"vendor": "M66B", "product": "FairEmail", "versions": [{"version": "< 1.2319", "status": "affected"}]}], "providerMetadata": {"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "shortName": "GitHub_M", "dateUpdated": "2026-09-17T20:17:47.341Z"}, "descriptions": [{"lang": "en", "value": "FairEmail is a fully featured, open source, privacy-friendly email app for Android. Prior to 1.2319, the ActivityAMP AMP message renderer in app/src/main/java/eu/faircode/email/ActivityAMP.java enables JavaScript in its WebView but incompletely sanitizes untrusted message HTML. For non-allowlisted hosts, script.removeAttr(\"src\") leaves inline script elements in the document and does not reject event-handler attributes or javascript: URLs on other elements. A crafted AMP email can execute arbitrary JavaScript when a recipient opens the message and enables the AMP toggle. The script can read the message DOM, exfiltrate message data, and display phishing overlays within the message-body area. Exploitation requires the recipient to enable the AMP toggle, and practical exposure is reduced because AMP email is uncommon. This issue is fixed in version 1.2319."}], "source": {"advisory": "GHSA-r8ff-qr7g-pvw6", "discovery": "UNKNOWN"}}, "adp": [{"metrics": [{"other": {"type": "ssvc", "content": {"timestamp": "2026-09-18T20:08:04.050901Z", "id": "CVE-2026-54521", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "role": "CISA Coordinator", "version": "2.0.3"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-09-18T20:08:14.389Z"}}]}}

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{"affected": [{"affectedData": [{"product": "FairEmail", "vendor": "M66B", "versions": [{"status": "affected", "version": "< 1.2319"}]}], "source": "[email protected]"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "FairEmail is a fully featured, open source, privacy-friendly email app for Android. Prior to 1.2319, the ActivityAMP AMP message renderer in app/src/main/java/eu/faircode/email/ActivityAMP.java enables JavaScript in its WebView but incompletely sanitizes untrusted message HTML. For non-allowlisted hosts, script.removeAttr(\"src\") leaves inline script elements in the document and does not reject event-handler attributes or javascript: URLs on other elements. A crafted AMP email can execute arbitrary JavaScript when a recipient opens the message and enables the AMP toggle. The script can read the message DOM, exfiltrate message data, and display phishing overlays within the message-body area. Exploitation requires the recipient to enable the AMP toggle, and practical exposure is reduced because AMP email is uncommon. This issue is fixed in version 1.2319."}], "id": "CVE-2026-54521", "lastModified": "2026-09-18T20:17:16.630", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 6.1, "baseSeverity": "MEDIUM", "confidentialityImpact": "LOW", "integrityImpact": "LOW", "privilegesRequired": "NONE", "scope": "CHANGED", "userInteraction": "REQUIRED", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N", "version": "3.1"}, "exploitabilityScore": 2.8, "impactScore": 2.7, "source": "[email protected]", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-54521", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "role": "CISA Coordinator", "timestamp": "2026-09-18T20:08:04.050901Z", "version": "2.0.3"}}]}, "published": "2026-09-17T21:17:16.397", "references": [{"source": "[email protected]", "url": "https://github.com/M66B/FairEmail/commit/fb37bbfabf5e75d08f0cfa6ce9b84469d62a20a0"}, {"source": "[email protected]", "url": "https://github.com/M66B/FairEmail/releases/tag/1.2319"}, {"source": "[email protected]", "url": "https://github.com/M66B/FairEmail/security/advisories/GHSA-r8ff-qr7g-pvw6"}], "sourceIdentifier": "[email protected]", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-79"}], "source": "[email protected]", "type": "Secondary"}]}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "[0,1.2319)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "cna", "scores": [{"score": 100.0, "source": "cna"}]}, "original": {"product": "FairEmail", "source": "cna", "vendor": "M66B"}, "product": "fairemail", "vendor": "m66b"}], "created": "2026-09-18T20:00:47.506558+00:00", "updated": "2026-09-19T02:30:17.317395+00:00", "vendors": ["m66b", "m66b$PRODUCT$fairemail"]}