GHSA-532v-xpq5-8h95 CVE-2026-34774

Electron: Use-after-free in offscreen child window paint callback

High npm

Severity: 8.1 / 10; High · CVSS 3.1
Exploit chance (EPSS): 0.45%; Chance of exploitation in the next 30 days. Higher than 39.30% of scored vulnerabilities.
Known exploited: No; Not in CISA's catalog
Weakness: CWE-416 Use After Free
Fix: 39.8.1; Upgrade electron to this version or later

Description

Impact

Apps that use offscreen rendering and allow child windows via window.open() may be vulnerable to a use-after-free. If the parent offscreen WebContents is destroyed while a child window remains open, subsequent paint frames on the child dereference freed memory, which may lead to a crash or memory corruption.

Apps are only affected if they use offscreen rendering (webPreferences.offscreen: true) and their setWindowOpenHandler permits child windows. Apps that do not use offscreen rendering, or that deny child windows, are not affected.

Workarounds

Deny child window creation from offscreen renderers in your setWindowOpenHandler, or ensure child windows are closed before the parent is destroyed.

Fixed Versions

41.0.0
40.7.0
39.8.1

For more information

If there are any questions or comments about this advisory, please email security@electronjs.org

Affected versions

npm

Package	Vulnerable	Fixed in
electron	`< 39.8.1`	`39.8.1`
electron	`>= 40.0.0-alpha.1, < 40.7.0`	`40.7.0`
electron	`>= 41.0.0-alpha.1, < 41.0.0`	`41.0.0`

How to fix

Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.

electron npm → `39.8.1`

npm

npm install electron@39.8.1

yarn

yarn add electron@39.8.1

pnpm

pnpm add electron@39.8.1

Severity breakdown

CVSS 3.1 8.1

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

Attack vector: Network
Attack complexity: High
Privileges required: None
User interaction: None
Scope: Unchanged
Confidentiality: High
Integrity: High
Availability: High

Weakness

CWE-416: Use After Free

The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.

How to prevent it

Architecture and Design: Choose a language that provides automatic memory management.
Implementation: When freeing pointers, be sure to set them to NULL once they are freed. However, the utilization of multiple or complex data structures may lower the usefulness of this strategy.

References

Advisories

nvd.nist.gov/vuln/detail/CVE-2026-34774

Packages

github.com/electron/electron

Timeline

Apr 3, 2026 Published
Jul 24, 2026 Last updated by the source
Nov 1, 2026 Latest EPSS score

Advisory	Severity	Why it's related
GHSA-qqvq-6xgj-jw8g Electron affected by libvpx's heap buffer overflow in vp8 encoding	High Known exploited	Also affects electron
GHSA-j7hp-h8jx-5ppr libwebp: OOB write in BuildHuffmanTable	High Known exploited	Also affects electron
GHSA-995f-9x5r-2rcj Heap buffer overflow in GPU	Critical Known exploited	Also affects electron
GHSA-jr5w-w6x2-84p9 Electron: Mitigation for compromised eMudhra intermediate certificates	High	Also affects electron
GHSA-h3v5-h239-pg29 Electron: Off-screen rendering on macOS trusts GPU-supplied frame geometry	Low	Also affects electron
GHSA-3qxv-5xgr-q7w9 Electron: Frame subscription trusts GPU-supplied frame geometry	Low	Also affects electron
GHSA-997q-gvvc-jwmx Electron: openExternal permission requests can be attributed to the wrong origin	Medium	Also affects electron
GHSA-fw47-9c62-h3vw Electron: HID and USB permission checks can be attributed to the wrong origin	Medium	Also affects electron

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