How severe is CVE-2026-70602?

CVE-2026-70602 has a CVSS score of 6.6/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2026-70602?

CVE-2026-70602 affects the following packages: electron (npm), electron (npm), electron (npm), electron (npm). Ecosystems affected: npm.

How do I fix CVE-2026-70602?

Update electron to 39.8.8 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-70602 is resolved across your whole dependency graph.

How do I detect CVE-2026-70602 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-2026-70602 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-2026-70602 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-70602 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-2026-70602?

CVE-2026-70602 has an EPSS (Exploit Prediction Scoring System) score of 0.3%, placing it in the 17th 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-2026-70602?

CVE-2026-70602 is classified as CWE-284 (CWE-284). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2026-70602 published, and has it been updated?

CVE-2026-70602 was published on August 5, 2026 and was last updated on October 28, 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

MEDIUM severity

CVE-2026-70602 — electron

MEDIUM

CVE-2026-70602 is a medium-severity (CVSS 6.6) CWE-284 vulnerability in electron. A fix is available for electron — see the affected versions and patch details below.

Electron: Extension tab APIs operate across session boundaries

Also known asGHSA-m55f-7gqj-fr98

Published

Aug 5, 2026

Updated

Oct 28, 2026

Affected

4 pkgs

Patched

4 / 4

Exploits

None indexed

Exploitation data as of Nov 4, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2026-70602.

EPSS Exploitation Probability

via FIRST.org ↗

0.3%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs17th percentile — riskier than 17% of all scored CVEsHighest risk

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

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

4 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

12.2Mdownloads / week

Description

Impact

Extension tab and scripting APIs were not scoped to the extension's own session. A malicious or compromised extension loaded into one session could navigate, script, and read from windows belonging to a different session.

Apps are only affected if they load Chrome extensions via session.loadExtension and rely on separate sessions to isolate that extension from other content. Apps that do not load extensions, or that use a single session, are not affected.

Workarounds

Only load extensions from sources you trust; do not rely on session separation alone to contain an extension.

Fixed Versions

42.0.0-beta.3
41.2.1
40.9.0
39.8.8

For more information

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

Affected Packages

4 total 4 fixed

Ecosystem	Package	Vulnerable range	Fix
📦npm	`electron`	all versions	39.8.8`npm install electron@39.8.8`
📦npm	`electron`	≥ 40.0.0-alpha.1&&< 40.9.0	40.9.0`npm install electron@40.9.0`
📦npm	`electron`	≥ 41.0.0-alpha.1&&< 41.2.1	41.2.1`npm install electron@41.2.1`
📦npm	`electron`	≥ 42.0.0-alpha.1&&< 42.0.0-beta.3	42.0.0-beta.3`npm install electron@42.0.0-beta.3`

Affected Products

1 product · 11 configurations

Application

electronelectronjs

≥ 41.0.0 && < 41.2.1

1 version

42.0.0

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 39.8.8 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-70602 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 Extension tab and scripting APIs were not scoped to the extension's own `session`. A malicious or compromised extension loaded into one session could navigate, script, and read from windows belonging to a different session. Apps are only affected if they load Chrome extensions via `session.loadExtension` and rely on separate sessions to isolate that extension from other content. Apps that do not load extensions, or that use a single session, are not affected. ### Workarounds Only load extensions from sources you trust; do not rely on session separation alone to contain an extensio