{"id":"CVE-2026-70604","aliases":["EUVD-2026-53440","GHSA-v3j7-r9gq-3gjw"],"status":"published","title":"Electron: Custom protocol with supportFetchAPI but not corsEnabled allows cross-origin reads","description":"Electron is a framework for writing cross-platform desktop applications using JavaScript, HTML and CSS. Prior to 39.8.10, 40.9.3, 41.4.0, and 42.0.0, a custom scheme registered with supportFetchAPI: true but without corsEnabled: true was not subject to CORS enforcement. A page loaded from a remote origin could therefore fetch() or XMLHttpRequest that scheme cross-origin and read the full response body, rather than the read being blocked. Apps that serve sensitive data from such a scheme and load remote or untrusted content in a renderer are affected. This issue is fixed in versions 39.8.10, 40.9.3, 41.4.0, and 42.0.0.","severity":{"version":"3.1","score":7.4,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:N/A:N","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-11","score":0.00354,"percentile":0.2956,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-942"],"published":"2026-08-05T15:59:24Z","modified":"2026-10-28T02:31:11Z","fixes":[{"ecosystem":"npm","package":"electron","fixed_in":["42.0.0","41.4.0","40.9.3","39.8.10"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"npm","package":"electron","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"42.0.0-alpha.1"},{"fixed":"42.0.0"}]}]},{"source":"ghsa","ecosystem":"npm","package":"electron","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"41.0.0-alpha.1"},{"fixed":"41.4.0"}]}]},{"source":"ghsa","ecosystem":"npm","package":"electron","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"40.0.0-alpha.1"},{"fixed":"40.9.3"}]}]},{"source":"ghsa","ecosystem":"npm","package":"electron","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"39.8.10"}]}]},{"source":"osv","ecosystem":"npm","package":"electron","ranges":[{"type":"SEMVER","events":[{"introduced":"42.0.0-alpha.1"},{"fixed":"42.0.0"}]}]},{"source":"osv","ecosystem":"npm","package":"electron","ranges":[{"type":"SEMVER","events":[{"introduced":"41.0.0-alpha.1"},{"fixed":"41.4.0"}]}]},{"source":"osv","ecosystem":"npm","package":"electron","ranges":[{"type":"SEMVER","events":[{"introduced":"40.0.0-alpha.1"},{"fixed":"40.9.3"}]}]},{"source":"osv","ecosystem":"npm","package":"electron","ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"39.8.10"}]}]}],"products":[{"vendor":"electron","product":"electron"},{"vendor":"electronjs","product":"electron"}],"references":[{"url":"https://github.com/electron/electron/security/advisories/GHSA-v3j7-r9gq-3gjw","tags":["x_refsource_CONFIRM","Vendor Advisory","advisory","web"]},{"url":"https://github.com/advisories/GHSA-v3j7-r9gq-3gjw"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/70xxx/CVE-2026-70604.json","tags":["advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-70604","tags":["advisory"]},{"url":"https://github.com/electron/electron","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2026-70604","title":"Electron: Custom protocol with supportFetchAPI but not corsEnabled allows cross-origin reads","description":"Electron is a framework for writing cross-platform desktop applications using JavaScript, HTML and CSS. Prior to 39.8.10, 40.9.3, 41.4.0, and 42.0.0, a custom scheme registered with supportFetchAPI: true but without corsEnabled: true was not subject to CORS enforcement. A page loaded from a remote origin could therefore fetch() or XMLHttpRequest that scheme cross-origin and read the full response body, rather than the read being blocked. Apps that serve sensitive data from such a scheme and load remote or untrusted content in a renderer are affected. This issue is fixed in versions 39.8.10, 40.9.3, 41.4.0, and 42.0.0.","status":"published","published":"2026-08-05T15:59:24.043Z","modified":"2026-08-05T18:41:32.481Z","cvss":[{"version":"3.1","score":7.4,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:N/A:N","level":"high","assessor":"cna"}],"cwes":["CWE-942"],"updated_at":"2026-11-02T13:35:10.963527Z"}],"euvd":[{"id":"EUVD-2026-53440","description":"Electron is a framework for writing cross-platform desktop applications using JavaScript, HTML and CSS. Prior to 39.8.10, 40.9.3, 41.4.0, and 42.0.0, a custom scheme registered with supportFetchAPI: true but without corsEnabled: true was not subject to CORS enforcement. A page loaded from a remote origin could therefore fetch() or XMLHttpRequest that scheme cross-origin and read the full response body, rather than the read being blocked. Apps that serve sensitive data from such a scheme and load remote or untrusted content in a renderer are affected. This issue is fixed in versions 39.8.10, 40.9.3, 41.4.0, and 42.0.0.","status":"published","published":"2026-08-05T15:59:24Z","modified":"2026-08-05T18:41:32Z","cvss":[{"version":"3.1","score":7.4,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:N/A:N","level":"high"}],"updated_at":"2026-11-02T18:02:09.520152Z"}],"ghsa":[{"id":"GHSA-v3j7-r9gq-3gjw","title":"Electron: Custom protocol with supportFetchAPI but not corsEnabled allows cross-origin reads","description":"### Impact\nA custom scheme registered with `supportFetchAPI: true` but without `corsEnabled: true` was not subject to CORS enforcement. A page loaded from a remote origin could therefore `fetch()` or `XMLHttpRequest` that scheme cross-origin and read the full response body, rather than the read being blocked.\n\nApps that serve sensitive data from such a scheme and load remote or untrusted content in a renderer are affected. Apps that set `corsEnabled: true`, or that do not load untrusted content, are not affected.\n\n### Workarounds\nSet `corsEnabled: true` on schemes that must enforce CORS, and validate the request `Origin` in your protocol handler before returning sensitive data.\n\n### Fixed Versions\n* `42.0.0`\n* `41.4.0`\n* `40.9.3`\n* `39.8.10`\n\n### For more information\nIf you have any questions or comments about this advisory, email Electron at [security@electronjs.org](mailto:security@electronjs.org)","status":"published","published":"2026-08-05T15:59:45Z","modified":"2026-08-05T15:59:46Z","cvss":[{"version":"3.1","score":7.4,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:N/A:N","level":"high"}],"cwes":["CWE-942"],"updated_at":"2026-11-02T14:40:56.852119Z"}],"nvd":[{"id":"CVE-2026-70604","description":"Electron is a framework for writing cross-platform desktop applications using JavaScript, HTML and CSS. Prior to 39.8.10, 40.9.3, 41.4.0, and 42.0.0, a custom scheme registered with supportFetchAPI: true but without corsEnabled: true was not subject to CORS enforcement. A page loaded from a remote origin could therefore fetch() or XMLHttpRequest that scheme cross-origin and read the full response body, rather than the read being blocked. Apps that serve sensitive data from such a scheme and load remote or untrusted content in a renderer are affected. This issue is fixed in versions 39.8.10, 40.9.3, 41.4.0, and 42.0.0.","status":"published","published":"2026-08-05T16:17:04.617Z","modified":"2026-10-08T13:53:51.593Z","cvss":[{"version":"3.1","score":7.4,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:N/A:N","level":"high","assessor":"secondary"}],"cwes":["CWE-942"],"updated_at":"2026-11-02T14:12:35.031043Z"}],"osv":[{"id":"CVE-2026-70604","title":"Electron: Custom protocol with supportFetchAPI but not corsEnabled allows cross-origin reads","description":"Electron is a framework for writing cross-platform desktop applications using JavaScript, HTML and CSS. Prior to 39.8.10, 40.9.3, 41.4.0, and 42.0.0, a custom scheme registered with supportFetchAPI: true but without corsEnabled: true was not subject to CORS enforcement. A page loaded from a remote origin could therefore fetch() or XMLHttpRequest that scheme cross-origin and read the full response body, rather than the read being blocked. Apps that serve sensitive data from such a scheme and load remote or untrusted content in a renderer are affected. This issue is fixed in versions 39.8.10, 40.9.3, 41.4.0, and 42.0.0.","status":"published","published":"2026-08-05T15:59:24.043Z","modified":"2026-10-28T02:31:11.532703316Z","cvss":[{"version":"3.1","score":7.4,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:N/A:N","level":"high"}],"cwes":["CWE-942"],"updated_at":"2026-11-02T15:45:15.164658Z"},{"id":"GHSA-v3j7-r9gq-3gjw","title":"Electron: Custom protocol with supportFetchAPI but not corsEnabled allows cross-origin reads","description":"### Impact\nA custom scheme registered with `supportFetchAPI: true` but without `corsEnabled: true` was not subject to CORS enforcement. A page loaded from a remote origin could therefore `fetch()` or `XMLHttpRequest` that scheme cross-origin and read the full response body, rather than the read being blocked.\n\nApps that serve sensitive data from such a scheme and load remote or untrusted content in a renderer are affected. Apps that set `corsEnabled: true`, or that do not load untrusted content, are not affected.\n\n### Workarounds\nSet `corsEnabled: true` on schemes that must enforce CORS, and validate the request `Origin` in your protocol handler before returning sensitive data.\n\n### Fixed Versions\n* `42.0.0`\n* `41.4.0`\n* `40.9.3`\n* `39.8.10`\n\n### For more information\nIf you have any questions or comments about this advisory, email Electron at [security@electronjs.org](mailto:security@electronjs.org)","status":"published","published":"2026-08-05T15:59:45Z","modified":"2026-08-05T16:26:04.421893Z","cvss":[{"version":"3.1","score":7.4,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:N/A:N","level":"high"}],"cwes":["CWE-942"],"updated_at":"2026-11-02T15:46:56.639206Z"}]}}