CVE-2026-34767 — electron
MEDIUMCVE-2026-34767 is a medium-severity (CVSS 5.9) CWE-74 vulnerability in electron. A fix is available for electron — see the affected versions and patch details below.
Electron: HTTP Response Header Injection in custom protocol handlers and webRequest
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-2026-34767.
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
Apps that register custom protocol handlers via protocol.handle() / protocol.registerSchemesAsPrivileged() or modify response headers via webRequest.onHeadersReceived may be vulnerable to HTTP response header injection if attacker-controlled input is reflected into a response header name or value.
An attacker who can influence a header value may be able to inject additional response headers, affecting cookies, content security policy, or cross-origin access controls.
Apps that do not reflect external input into response headers are not affected.
Workarounds
Validate or sanitize any untrusted input before including it in a response header name or value.
Fixed Versions
41.0.340.8.339.8.338.8.6
For more information
If there are any questions or comments about this advisory, send an email to [email protected]
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | electron | all versions | 38.8.6npm install electron@38.8.6 |
| 📦npm | electron | ≥ 39.0.0-alpha.1&&< 39.8.3 | 39.8.3npm install electron@39.8.3 |
| 📦npm | electron | ≥ 40.0.0-alpha.1&&< 40.8.3 | 40.8.3npm install electron@40.8.3 |
| 📦npm | electron | ≥ 41.0.0-alpha.1&&< 41.0.3 | 41.0.3npm install electron@41.0.3 |
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 38.8.6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-34767 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.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.Source: Red Hat security advisory for CVE-2026-34767 (CC BY 4.0)
Frequently Asked Questions
Is CVE-2026-34767 in your dependencies?
Find it across npm, including transitive dependencies.