{"id":"CVE-2026-34776","aliases":["GHSA-3c8v-cfp5-9885"],"url":"https://o3.security/vulnerability/CVE-2026-34776","summary":"Electron: Out-of-bounds read in second-instance IPC on macOS and Linux","details":"### Impact\nOn macOS and Linux, apps that call `app.requestSingleInstanceLock()` were vulnerable to an out-of-bounds heap read when parsing a crafted second-instance message. Leaked memory could be delivered to the app's `second-instance` event handler.\n\nThis issue is limited to processes running as the same user as the Electron app.\n\nApps that do not call `app.requestSingleInstanceLock()` are not affected. Windows is not affected by this issue.\n\n### Workarounds\nThere are no app side workarounds, developers must update to a patched version of Electron.\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":"2026-04-03T23:56:42.200Z","modified":"2026-10-28T11:12:12.785324119Z","cvss":{"score":5.3,"severity":"MEDIUM","vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:L"},"epss":null,"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-2026-34776.json"},{"type":"ADVISORY","url":"https://github.com/electron/electron/security/advisories/GHSA-3c8v-cfp5-9885"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-34776"},{"type":"PACKAGE","url":"https://github.com/electron/electron"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-10-28T11:12:12.785324119Z"}}