CVE-2026-34776

MEDIUMCVSS 5.3/10EPSS 0.22%

Last modified

CVE-2026-34776 is a medium-severity vulnerability rated 5.3/10 on the CVSS scale. 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. EPSS estimates a 0.22% chance of exploitation in the next 30 days.

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, 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.

Metrics

CVSS 3.1
5.3/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

EPSS Probability
0.22%

12.3th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersionsUpdate
ElectronjsElectron< 38.8.6
ElectronjsElectron>= 39.0.0, < 39.8.1
ElectronjsElectron>= 40.0.0, < 40.8.1
ElectronjsElectron41.0.0Alpha1

References

Timeline

Published
Last Modified
Status
Analyzed

Frequently Asked Questions

What is CVE-2026-34776?
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.
How severe is CVE-2026-34776?
CVE-2026-34776 has a CVSS score of 5.3/10 (MEDIUM severity). The EPSS model estimates a 0.22% probability of exploitation in the next 30 days.
How do I fix CVE-2026-34776?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2026-34776?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST