GHSA-vv43-5jgx-7qv8 CVE-2026-102672

Electron: Local race condition in Squirrel.Mac update installation on macOS

Medium npm

Severity: 6.7 / 10; Medium · CVSS 3.1
Exploit chance (EPSS): 0.09%; Chance of exploitation in the next 30 days. Higher than 0.52% of scored vulnerabilities.
Known exploited: No; Not in CISA's catalog
Weakness: CWE-367 Time-of-check Time-of-use (TOCTOU) Race Condition
Fix: 39.8.10; Upgrade electron to this version or later

Description

Impact

On macOS, Electron bundles the Squirrel.Mac auto-update framework, whose privileged ShipIt helper performs the final step of an update as root. A local attacker could cause that helper to overwrite a different application's files, as root, instead of the app that started the update. Exploitation requires local access to the machine.

Apps are only affected on macOS if they ship Squirrel.Mac-based auto-updates. Apps on other platforms, or that do not use Squirrel.Mac auto-updates, are not affected.

Workarounds

There are no app side workarounds, you must update to a patched version of Electron.

Fixed Versions

42.0.0-beta.2
41.10.5
39.8.10

For more information

If you have any questions or comments about this advisory, email us at security@electronjs.org

Affected versions

npm

Package	Vulnerable	Fixed in
electron	`< 39.8.10`	`39.8.10`
electron	`>= 40.0.0-alpha.1, < 41.10.5`	`41.10.5`
electron	`>= 42.0.0-alpha.1, < 42.0.0-beta.2`	`42.0.0-beta.2`

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 → `39.8.10`

npm

npm install electron@39.8.10

yarn

yarn add electron@39.8.10

pnpm

pnpm add electron@39.8.10

Severity breakdown

CVSS 3.1 6.7

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

Attack vector: Local
Attack complexity: High
Privileges required: Low
User interaction: Required
Scope: Unchanged
Confidentiality: High
Integrity: High
Availability: High

Weakness

CWE-367: Time-of-check Time-of-use (TOCTOU) Race Condition

The product checks the state of a resource before using that resource, but the resource's state can change between the check and the use in a way that invalidates the results of the check.

How to prevent it

Implementation: The most basic advice for TOCTOU vulnerabilities is to not perform a check before the use. This does not resolve the underlying issue of the execution of a function on a resource whose state and identity cannot be assured, but it does help to limit the false sense of security given by the check.
Implementation: When the file being altered is owned by the current user and group, set the effective gid and uid to that of the current user and group when executing this statement.
Architecture and Design: Limit the interleaving of operations on files from multiple processes.
Implementation, Architecture and Design: If you cannot perform operations atomically and you must share access to the resource between multiple processes or threads, then try to limit the amount of time (CPU cycles) between the check and use of the resource. This will not fix the problem, but it could make it more difficult for an attack to succeed.
Implementation: Recheck the resource after the use call to verify that the action was taken appropriately.
Architecture and Design: Ensure that some environmental locking mechanism can be used to protect resources effectively.
Implementation: Ensure that locking occurs before the check, as opposed to afterwards, such that the resource, as checked, is the same as it is when in use.

References

Packages

github.com/electron/electron

Timeline

Sep 29, 2026 Published
Oct 16, 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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