How severe is CVE-2021-39184?

CVE-2021-39184 has a CVSS score of 8.6/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by CVE-2021-39184?

CVE-2021-39184 affects the following packages: electron (npm), electron (npm), electron (npm). Ecosystems affected: npm.

How do I fix CVE-2021-39184?

Update electron to 11.5.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-39184 is resolved across your whole dependency graph.

How do I detect CVE-2021-39184 in my npm dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for electron, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2021-39184 if there is no patch (or I can't update yet)?

Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used.

Is CVE-2021-39184 actively exploited in the wild?

No public exploit code has been indexed for CVE-2021-39184 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2021-39184?

CVE-2021-39184 has an EPSS (Exploit Prediction Scoring System) score of 1.1%, placing it in the 63th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2021-39184?

CVE-2021-39184 is classified as CWE-668 (CWE-668), CWE-862 (CWE-862). These weakness types describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2021-39184 published, and has it been updated?

CVE-2021-39184 was published on October 12, 2021 and was last updated on August 7, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

📦

📦 npm

Not in CISA KEV

HIGH severity

CVE-2021-39184 — electron

HIGHFix: electron/electron#30728

CVE-2021-39184 is a high-severity (CVSS 8.6) CWE-668 vulnerability in electron. A fix is available for electron — see the affected versions and patch details below.

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

Also known asGHSA-mpjm-v997-c4h4

Published

Oct 12, 2021

Updated

Aug 7, 2026

Affected

3 pkgs

Patched

3 / 3

Exploits

None indexed

Exploitation data as of Oct 10, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

1.1%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs63th percentile — riskier than 63% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

CVE-2021-39184 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.

Where this sits among everything scored

Of 385,386 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.

Real-World Exposure

3 pkgs affected

How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.

2Kother npm packages depend on this — each one inherits the vulnerability until it's patched upstream

electronnpm

7.7Mdownloads / week

Description

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:

delete require('electron').nativeImage.createThumbnailFromPath

For more information

If you have any questions or comments about this advisory, email us at [email protected].

Affected Packages

3 total 3 fixed

Ecosystem	Package	Vulnerable range	Fix
📦npm	`electron`	all versions	11.5.0`npm install electron@11.5.0`
📦npm	`electron`	≥ 12.0.0&&< 12.1.0	12.1.0`npm install electron@12.1.0`
📦npm	`electron`	≥ 13.0.0&&< 13.3.0	13.3.0`npm install electron@13.3.0`

Affected Products

1 product · 37 configurations

Application

electronelectronjs

≥ 13.0.0 && < 13.3.0

2 versions

14.0.015.0.0

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for electron, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update electron to 11.5.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-39184 is resolved across your whole dependency graph.
Workarounds
Put an independent control in front of the weakness: restrict the affected endpoint or interface to trusted networks, require an additional authentication factor or proxy-level check, and invalidate existing sessions and credentials in case the flaw has already been used.

Frequently Asked Questions

### 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