{"id":"CVE-2026-34778","aliases":["GHSA-xj5x-m3f3-5x3h"],"url":"https://o3.security/vulnerability/CVE-2026-34778","summary":"Electron: Service worker can spoof executeJavaScript IPC replies","details":"### 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)","published":"2026-04-03T23:59:07.419Z","modified":"2026-08-12T16:23:48.766885Z","cvss":{"score":5.9,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:H/A:N"},"epss":{"score":0.00123,"percentile":0.02325,"asOf":"2026-08-26"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"npm","name":"electron","fixedVersion":"38.8.6"},{"ecosystem":"npm","name":"electron","fixedVersion":"39.8.1"},{"ecosystem":"npm","name":"electron","fixedVersion":"40.8.1"},{"ecosystem":"npm","name":"electron","fixedVersion":"41.0.0"}],"fix":null,"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/34xxx/CVE-2026-34778.json"},{"type":"ADVISORY","url":"https://github.com/electron/electron/security/advisories/GHSA-xj5x-m3f3-5x3h"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-34778"},{"type":"PACKAGE","url":"https://github.com/electron/electron"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T16:23:48.766885Z"}}