{"id":"CVE-2026-34778","aliases":["EUVD-2026-18955","GHSA-xj5x-m3f3-5x3h"],"status":"published","title":"Electron: Service worker can spoof executeJavaScript IPC replies","description":"Electron is a framework for writing cross-platform desktop applications using JavaScript, HTML and CSS. Prior to versions 38.8.6, 39.8.1, 40.8.1, and 41.0.0, a service worker running in a session could spoof reply messages on the internal IPC channel used by webContents.executeJavaScript() and related methods, causing the main-process promise to resolve with attacker-controlled data. Apps are only affected if they have service workers registered and use the result of webContents.executeJavaScript() (or webFrameMain.executeJavaScript()) in security-sensitive decisions. This issue has been patched in versions 38.8.6, 39.8.1, 40.8.1, and 41.0.0.","severity":{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:H/A:N","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-11","score":0.00129,"percentile":0.02586,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-290","CWE-345"],"published":"2026-04-03T02:44:59Z","modified":"2026-10-28T11:12:12Z","fixes":[{"ecosystem":"npm","package":"electron","fixed_in":["38.8.6","39.8.1","40.8.1","41.0.0"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"npm","package":"electron","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"38.8.6"}]}]},{"source":"ghsa","ecosystem":"npm","package":"electron","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"39.0.0-alpha.1"},{"fixed":"39.8.1"}]}]},{"source":"ghsa","ecosystem":"npm","package":"electron","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"40.0.0-alpha.1"},{"fixed":"40.8.1"}]}]},{"source":"ghsa","ecosystem":"npm","package":"electron","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"41.0.0-alpha.1"},{"fixed":"41.0.0"}]}]},{"source":"osv","ecosystem":"npm","package":"electron","ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"38.8.6"}]}]},{"source":"osv","ecosystem":"npm","package":"electron","ranges":[{"type":"SEMVER","events":[{"introduced":"39.0.0-alpha.1"},{"fixed":"39.8.1"}]}]},{"source":"osv","ecosystem":"npm","package":"electron","ranges":[{"type":"SEMVER","events":[{"introduced":"40.0.0-alpha.1"},{"fixed":"40.8.1"}]}]},{"source":"osv","ecosystem":"npm","package":"electron","ranges":[{"type":"SEMVER","events":[{"introduced":"41.0.0-alpha.1"},{"fixed":"41.0.0"}]}]}],"products":[{"vendor":"electron","product":"electron"},{"vendor":"electronjs","product":"electron"}],"references":[{"url":"https://github.com/electron/electron/security/advisories/GHSA-xj5x-m3f3-5x3h","tags":["x_refsource_CONFIRM","Vendor Advisory","advisory","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-34778","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-xj5x-m3f3-5x3h"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/34xxx/CVE-2026-34778.json","tags":["advisory"]},{"url":"https://github.com/electron/electron","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2026-34778","title":"Electron: Service worker can spoof executeJavaScript IPC replies","description":"Electron is a framework for writing cross-platform desktop applications using JavaScript, HTML and CSS. Prior to versions 38.8.6, 39.8.1, 40.8.1, and 41.0.0, a service worker running in a session could spoof reply messages on the internal IPC channel used by webContents.executeJavaScript() and related methods, causing the main-process promise to resolve with attacker-controlled data. Apps are only affected if they have service workers registered and use the result of webContents.executeJavaScript() (or webFrameMain.executeJavaScript()) in security-sensitive decisions. This issue has been patched in versions 38.8.6, 39.8.1, 40.8.1, and 41.0.0.","status":"published","published":"2026-04-03T23:59:07.419Z","modified":"2026-04-06T15:50:49.205Z","cvss":[{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:H/A:N","level":"medium","assessor":"cna"}],"cwes":["CWE-290","CWE-345"],"updated_at":"2026-11-02T14:20:14.665567Z"}],"euvd":[{"id":"EUVD-2026-18955","description":"Electron is a framework for writing cross-platform desktop applications using JavaScript, HTML and CSS. Prior to versions 38.8.6, 39.8.1, 40.8.1, and 41.0.0, a service worker running in a session could spoof reply messages on the internal IPC channel used by webContents.executeJavaScript() and related methods, causing the main-process promise to resolve with attacker-controlled data. Apps are only affected if they have service workers registered and use the result of webContents.executeJavaScript() (or webFrameMain.executeJavaScript()) in security-sensitive decisions. This issue has been patched in versions 38.8.6, 39.8.1, 40.8.1, and 41.0.0.","status":"published","published":"2026-04-03T23:59:07Z","modified":"2026-04-06T15:50:49Z","cvss":[{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:H/A:N","level":"medium"}],"updated_at":"2026-11-02T19:25:15.794407Z"}],"ghsa":[{"id":"GHSA-xj5x-m3f3-5x3h","title":"Electron: Service worker can spoof executeJavaScript IPC replies","description":"### Impact\nA service worker running in a session could spoof reply messages on the internal IPC channel used by `webContents.executeJavaScript()` and related methods, causing the main-process promise to resolve with attacker-controlled data.\n\nApps are only affected if they have service workers registered and use the result of `webContents.executeJavaScript()` (or `webFrameMain.executeJavaScript()`) in security-sensitive decisions.\n\n### Workarounds\nDo not trust the return value of `webContents.executeJavaScript()` for security decisions. Use dedicated, validated IPC channels for security-relevant communication with renderers.\n\n### Fixed Versions\n* `41.0.0`\n* `40.8.1`\n* `39.8.1`\n* `38.8.6`\n\n### For more information\nIf there are any questions or comments about this advisory, please email [security@electronjs.org](mailto:security@electronjs.org)","status":"published","published":"2026-04-03T02:44:59Z","modified":"2026-04-06T23:11:12Z","cvss":[{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:H/A:N","level":"medium"}],"cwes":["CWE-290","CWE-345"],"updated_at":"2026-11-02T14:39:50.076383Z"}],"nvd":[{"id":"CVE-2026-34778","description":"Electron is a framework for writing cross-platform desktop applications using JavaScript, HTML and CSS. Prior to versions 38.8.6, 39.8.1, 40.8.1, and 41.0.0, a service worker running in a session could spoof reply messages on the internal IPC channel used by webContents.executeJavaScript() and related methods, causing the main-process promise to resolve with attacker-controlled data. Apps are only affected if they have service workers registered and use the result of webContents.executeJavaScript() (or webFrameMain.executeJavaScript()) in security-sensitive decisions. This issue has been patched in versions 38.8.6, 39.8.1, 40.8.1, and 41.0.0.","status":"published","published":"2026-04-04T00:16:19.06Z","modified":"2026-07-24T22:10:00.14Z","cvss":[{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:H/A:N","level":"medium","assessor":"secondary"},{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N","level":"medium","assessor":"primary"}],"cwes":["CWE-290","CWE-345"],"updated_at":"2026-11-02T14:12:13.1424Z"}],"osv":[{"id":"CVE-2026-34778","title":"Electron: Service worker can spoof executeJavaScript IPC replies","description":"Electron is a framework for writing cross-platform desktop applications using JavaScript, HTML and CSS. Prior to versions 38.8.6, 39.8.1, 40.8.1, and 41.0.0, a service worker running in a session could spoof reply messages on the internal IPC channel used by webContents.executeJavaScript() and related methods, causing the main-process promise to resolve with attacker-controlled data. Apps are only affected if they have service workers registered and use the result of webContents.executeJavaScript() (or webFrameMain.executeJavaScript()) in security-sensitive decisions. This issue has been patched in versions 38.8.6, 39.8.1, 40.8.1, and 41.0.0.","status":"published","published":"2026-04-03T23:59:07.419Z","modified":"2026-10-28T11:12:12.383333884Z","cvss":[{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:H/A:N","level":"medium"}],"cwes":["CWE-290","CWE-345"],"updated_at":"2026-11-02T15:45:02.247031Z"},{"id":"GHSA-xj5x-m3f3-5x3h","title":"Electron: Service worker can spoof executeJavaScript IPC replies","description":"### Impact\nA service worker running in a session could spoof reply messages on the internal IPC channel used by `webContents.executeJavaScript()` and related methods, causing the main-process promise to resolve with attacker-controlled data.\n\nApps are only affected if they have service workers registered and use the result of `webContents.executeJavaScript()` (or `webFrameMain.executeJavaScript()`) in security-sensitive decisions.\n\n### Workarounds\nDo not trust the return value of `webContents.executeJavaScript()` for security decisions. Use dedicated, validated IPC channels for security-relevant communication with renderers.\n\n### Fixed Versions\n* `41.0.0`\n* `40.8.1`\n* `39.8.1`\n* `38.8.6`\n\n### For more information\nIf there are any questions or comments about this advisory, please email [security@electronjs.org](mailto:security@electronjs.org)","status":"published","published":"2026-04-03T02:44:59Z","modified":"2026-04-06T23:20:03.66645Z","cvss":[{"version":"3.1","score":5.9,"vector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:H/A:N","level":"medium"}],"cwes":["CWE-290","CWE-345"],"updated_at":"2026-11-02T15:47:00.198893Z"}]}}