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
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
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
Impact
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. Apps that set an explicit session, or that do not isolate content across sessions, are not affected.
Workarounds
Set ProtocolResponse.session explicitly so the request uses the intended session's cache.
Fixed Versions
43.0.042.5.141.9.140.10.6
For more information
If you have any questions or comments about this advisory, email Electron at [email protected]
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 |
Affected Products
electronelectronjsDetection & 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.
Frequently Asked Questions
Is CVE-2026-70606 in your dependencies?
Find it across npm, including transitive dependencies.