CVE-2026-70606 — electron
MEDIUMCVE-2026-70606 is a medium-severity (CVSS 5.9) CWE-668 vulnerability in electron. A fix is available for electron — see the affected versions and patch details below.
Electron: ProtocolResponse.url reuses the default session cache instead of the registering session
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-2026-70606.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2026-70606 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,166 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
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.
electronnpmDescription
Electron is a framework for writing cross-platform desktop applications using JavaScript, HTML and CSS. Prior to 40.10.6, 41.9.1, 42.5.1, and 43.0.0, when a custom protocol handler returned a ProtocolResponse with a url and no session, Electron made the upstream request through defaultSession instead of the session that handled the protocol. A cached response could then be reused across otherwise isolated session partitions. Apps that use ProtocolResponse.url, omit ProtocolResponse.session, and rely on separate sessions to isolate content are affected. This issue is fixed in versions 40.10.6, 41.9.1, 42.5.1, and 43.0.0.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | electron | ≥ 43.0.0-alpha.1&&< 43.0.0 | 43.0.0npm install electron@43.0.0 |
| 📦npm | electron | ≥ 42.0.0-alpha.1&&< 42.5.1 | 42.5.1npm install electron@42.5.1 |
| 📦npm | electron | ≥ 41.0.0-alpha.1&&< 41.9.1 | 41.9.1npm install electron@41.9.1 |
| 📦npm | electron | ≥ 40.0.0-alpha.1&&< 40.10.6 | 40.10.6npm install electron@40.10.6 |
Detection & mitigation playbook
Open-source dependencyDetect
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 43.0.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-70606 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-70606 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2026-70606. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-70606 in your dependencies?
O3 Security finds CVE-2026-70606 across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.