CVE-2026-34776
Electron: Out-of-bounds read in second-instance IPC on macOS and Linux
CVE-2026-34776 is a medium vulnerability (CVSS 5.3) in Electron, published April 3, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.22%, the 12th percentile. Fixed in electron 38.8.6.
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, on 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. This issue is limited to processes running as the same user as the Electron app. Apps that do not call app.requestSingleInstanceLock() are not affected. Windows is not affected by this issue. This issue has been patched in versions 38.8.6, 39.8.1, 40.8.1, and 41.0.0.
Attack profile
How easy it is to exploit
- Attack vector
- Local
- Complexity
- High
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- None
- Availability
- Low
Exploit likelihood
What each source reports
CVE List Score used
Electron: Out-of-bounds read in second-instance IPC on macOS and Linux
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, on 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. This issue is limited to processes running as the same user as the Electron app. Apps that do not call app.requestSingleInstanceLock() are not affected. Windows is not affected by this issue. This issue has been patched in versions 38.8.6, 39.8.1, 40.8.1, and 41.0.0.
- Record
CVE-2026-34776- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:L - Weakness
- CWE-125
- Updated
- 2026-11-02
EUVDEUVD-2026-18951
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, on 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. This issue is limited to processes running as the same user as the Electron app. Apps that do not call app.requestSingleInstanceLock() are not affected. Windows is not affected by this issue. This issue has been patched in versions 38.8.6, 39.8.1, 40.8.1, and 41.0.0.
- Record
EUVD-2026-18951- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:L - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-3c8v-cfp5-9885
Electron: Out-of-bounds read in second-instance IPC on macOS and Linux
Impact
On 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.
This issue is limited to processes running as the same user as the Electron app.
Apps that do not call app.requestSingleInstanceLock() are not affected. Windows is not affected by this issue.
Workarounds
There are no app side workarounds, developers must update to a patched version of Electron.
Fixed Versions
41.0.040.8.139.8.138.8.6
For more information
If there are any questions or comments about this advisory, please email [email protected]
- Record
GHSA-3c8v-cfp5-9885- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:L - Weakness
- CWE-125
- Updated
- 2026-11-02
NVD
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, on 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. This issue is limited to processes running as the same user as the Electron app. Apps that do not call app.requestSingleInstanceLock() are not affected. Windows is not affected by this issue. This issue has been patched in versions 38.8.6, 39.8.1, 40.8.1, and 41.0.0.
- Record
CVE-2026-34776- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:L - CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N - Weakness
- CWE-125
- Updated
- 2026-11-02
OSV
Electron: Out-of-bounds read in second-instance IPC on macOS and Linux
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, on 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. This issue is limited to processes running as the same user as the Electron app. Apps that do not call app.requestSingleInstanceLock() are not affected. Windows is not affected by this issue. This issue has been patched in versions 38.8.6, 39.8.1, 40.8.1, and 41.0.0.
- Record
CVE-2026-34776- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:L - Weakness
- CWE-125
- Updated
- 2026-11-02
OSVGHSA-3c8v-cfp5-9885
Electron: Out-of-bounds read in second-instance IPC on macOS and Linux
Impact
On 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.
This issue is limited to processes running as the same user as the Electron app.
Apps that do not call app.requestSingleInstanceLock() are not affected. Windows is not affected by this issue.
Workarounds
There are no app side workarounds, developers must update to a patched version of Electron.
Fixed Versions
41.0.040.8.139.8.138.8.6
For more information
If there are any questions or comments about this advisory, please email [email protected]
- Record
GHSA-3c8v-cfp5-9885- CVSS 3.1
- 5.3 Medium
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:L - Weakness
- CWE-125
- Updated
- 2026-11-02
Affected products
Affected packages
History
| When | Changed | Sources |
|---|---|---|
| 2026-11-02 | created | CVE List, EUVD, GitHub Advisories, NVD, OSV |