Electron's sandboxed renderers can obtain thumbnails of arbitrary files through the nativeImage API

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

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

EPSS

• CVE-2021-39184: 1.05% estimated exploitation activity in the next 30 days; percentile 64.32 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Impact This vulnerability allows a sandboxed renderer to request a "thumbnail" image of an arbitrary file on the user's system. The thumbnail can potentially include significant parts of the original file, including textual data in many cases. All current stable versions of Electron are affected. Patches This was fixed with #30728, and the following Electron versions contain the fix: - 15.0.0-alpha.10 - 14.0.0 - 13.3.0 - 12.1.0 - 11.5.0 Workarounds If your app enables contextIsolation, this vulnerability is significantly more difficult for an attacker to exploit. Further, if your app does not depend on the createThumbnailFromPath API, then you can simply disable the functionality. In the main process, before the 'ready' event: For more information If you have any questions or comments about this advisory, email us at security@electronjs.org.

Published by the source

12 Oct 2021, 21:59 UTC

Last modified by the source

8 Jul 2026, 06:29 UTC

Source last checked

26 Oct 2026, 12:17 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-mpjm-v997-c4h4

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-mpjm-v997-c4h4

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# Patch Next advisory brief: CVE-2021-39184

Advisory: Electron's sandboxed renderers can obtain thumbnails of arbitrary files through the nativeImage API
IDs: CVE-2021-39184, GHSA-mpjm-v997-c4h4
Record: https://patchnext.com/advisories/cve-2021-39184 (revision 2, source checked 26 Oct 2026, 12:17 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.8)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: electron 13.3.0, 12.1.0, 11.5.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm electron: affected < 11.5.0; >= 12.0.0, < 12.1.0; >= 13.0.0, < 13.3.0; fixed in 13.3.0, 11.5.0, 12.1.0

## Suggested inspection (read-only)
- `npm ls electron --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on electron.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-mpjm-v997-c4h4 (OSV record GHSA-mpjm-v997-c4h4 lists affected ranges: npm electron >=0 =12.0.0 =13.0.0 <13.3.0 (fixed))
- Verified: https://github.com/advisories/GHSA-mpjm-v997-c4h4 (GitHub-reviewed advisory GHSA-mpjm-v997-c4h4 lists affected ranges: npm electron >=0 =12.0.0 =13.0.0 <13.3.0)

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