{"id":"CVE-2026-54521","state":"PUBLISHED","title":"FairEmail: Cross-site scripting (XSS) in AMP message rendering (ActivityAMP)","description":"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.","publishedAt":"2026-09-17T20:17:47.341Z","updatedAt":"2026-09-18T20:08:14.389Z","severity":{"score":6.1,"label":"Medium","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","source":"GitHub_M"},"assigner":"GitHub_M","products":["M66B FairEmail"],"affected":[{"vendor":"M66B","product":"FairEmail","versions":[{"version":"< 1.2319","status":"affected"}]}],"references":["https://github.com/M66B/FairEmail/security/advisories/GHSA-r8ff-qr7g-pvw6","https://github.com/M66B/FairEmail/commit/fb37bbfabf5e75d08f0cfa6ce9b84469d62a20a0","https://github.com/M66B/FairEmail/releases/tag/1.2319"],"weaknesses":["CWE-79"],"ingestedAt":"2026-10-29T20:12:24.861Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/54xxx/CVE-2026-54521.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-54521","state":"PUBLISHED","datePublished":"2026-09-17T20:17:47.341Z","dateUpdated":"2026-09-18T20:08:14.389Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-06-15T18:40:01.651Z"},"containers":{"cna":{"title":"FairEmail: Cross-site scripting (XSS) in AMP message rendering (ActivityAMP)","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."}],"affected":[{"vendor":"M66B","product":"FairEmail","versions":[{"version":"< 1.2319","status":"affected"}]}],"references":[{"url":"https://github.com/M66B/FairEmail/security/advisories/GHSA-r8ff-qr7g-pvw6","name":"https://github.com/M66B/FairEmail/security/advisories/GHSA-r8ff-qr7g-pvw6","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/M66B/FairEmail/commit/fb37bbfabf5e75d08f0cfa6ce9b84469d62a20a0","name":"https://github.com/M66B/FairEmail/commit/fb37bbfabf5e75d08f0cfa6ce9b84469d62a20a0","tags":["x_refsource_MISC"]},{"url":"https://github.com/M66B/FairEmail/releases/tag/1.2319","name":"https://github.com/M66B/FairEmail/releases/tag/1.2319","tags":["x_refsource_MISC"]}],"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"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-79","lang":"en","description":"CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-09-17T20:17:47.341Z"},"source":{"advisory":"GHSA-r8ff-qr7g-pvw6","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","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"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-09-18T20:08:14.389Z"}}]}}}