CVE-2026-34767: Electron HTTP Response Header Injection Vulnerability
MODERATECVE-2026-34767 is a MODERATE (CVSS 5.9) http response header injection vulnerability (CWE-113: Improper Neutralization of CRLF Sequences in HTTP Headers ('HTTP Request/Response Splitting')) affecting Electron libraries in the npm ecosystem. The issue involves http response header injection in custom protocol handlers and webrequest. Remediation is available by upgrading affected packages to version 38.8.6, 39.8.3, 40.8.3, 41.0.3.
CVE-2026-34767 at a Glance
Security Impact
CVSS: 5.9
The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:H/A:N).
How to Fix CVE-2026-34767
To remediate this vulnerability, upgrade all affected Electron dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.
npm install electron@38.8.6npm install electron@39.8.3npm install electron@40.8.3npm install electron@41.0.3Run the following command in your project directory to verify that all resolved dependencies use the patched release:
npm ls electronHow to Check if You Are Affected
To determine whether your Node.js application is affected by CVE-2026-34767, inspect your project dependencies using npm:
npm ls electronAnalyze the terminal output to locate any version of Electron in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 38.8.6), your application is affected.
Note: The npm ls electron command inspects dependencies declared in your package.json and lockfile; it does not perform automated runtime dynamic scanning.
Technical Details
Vulnerability Mechanism & Technical Analysis
This vulnerability is classified under CWE-113: Improper Neutralization of CRLF Sequences in HTTP Headers ('HTTP Request/Response Splitting'), where the product receives data from an http agent/component (e.g., web server, proxy, browser, etc.), but it does not neutralize or incorrectly neutralizes cr and lf characters before the data is included in outgoing http headers. In Electron, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.
Source Advisory Statement
CVE-2026-34767 Affected Electron Versions
4 component(s)| Product / Package | Ecosystem | Affected Versions | Fixed Version |
|---|---|---|---|
|
electron
|
npm |
< 38.8.6
|
38.8.6
|
|
electron
|
npm |
≥ 39.0.0-alpha.1
< 39.8.3
|
39.8.3
|
|
electron
|
npm |
≥ 40.0.0-alpha.1
< 40.8.3
|
40.8.3
|
|
electron
|
npm |
≥ 41.0.0-alpha.1
< 41.0.3
|
41.0.3
|
References
Frequently Asked Questions
What is CVE-2026-34767?
Which Electron versions are affected?
What version fixes CVE-2026-34767?
Is electron affected?
What is the CVSS score of CVE-2026-34767?
What CWE is associated with CVE-2026-34767?
How can I check npm dependencies for CVE-2026-34767?
Machine-readable OSV JSON
OSV v1.5 Schema
{
"schema_version" : "1.4.0",
"id" : "GHSA-4p4r-m79c-wq3v",
"modified" : "2026-04-06T23:10:30Z",
"published" : "2026-04-03T02:37:24Z",
"aliases" : [ "CVE-2026-34767" ],
"summary" : "Electron: HTTP Response Header Injection in custom protocol handlers and webRequest",
"details" : "### Impact\nApps 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.\n\nAn 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.\n\nApps that do not reflect external input into response headers are not affected.\n\n### Workarounds\nValidate or sanitize any untrusted input before including it in a response header name or value.\n\n### Fixed Versions\n* `41.0.3`\n* `40.8.3`\n* `39.8.3`\n* `38.8.6`\n\n### For more information\nIf there are any questions or comments about this advisory, send an email to [security@electronjs.org](mailto:security@electronjs.org)",
"severity" : [ {
"type" : "CVSS_V3",
"score" : "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:H/A:N"
} ],
"affected" : [ {
"package" : {
"ecosystem" : "npm",
"name" : "electron"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "0"
}, {
"fixed" : "38.8.6"
} ]
} ]
}, {
"package" : {
"ecosystem" : "npm",
"name" : "electron"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "39.0.0-alpha.1"
}, {
"fixed" : "39.8.3"
} ]
} ]
}, {
"package" : {
"ecosystem" : "npm",
"name" : "electron"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "40.0.0-alpha.1"
}, {
"fixed" : "40.8.3"
} ]
} ]
}, {
"package" : {
"ecosystem" : "npm",
"name" : "electron"
},
"ranges" : [ {
"type" : "ECOSYSTEM",
"events" : [ {
"introduced" : "41.0.0-alpha.1"
}, {
"fixed" : "41.0.3"
} ]
} ]
} ],
"references" : [ {
"type" : "WEB",
"url" : "https://github.com/electron/electron/security/advisories/GHSA-4p4r-m79c-wq3v"
}, {
"type" : "ADVISORY",
"url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-34767"
}, {
"type" : "PACKAGE",
"url" : "https://github.com/electron/electron"
} ],
"database_specific" : {
"cwe_ids" : [ "CWE-113", "CWE-74" ],
"severity" : "MODERATE",
"github_reviewed" : true,
"github_reviewed_at" : "2026-04-03T02:37:24Z",
"nvd_published_at" : "2026-04-04T00:16:17Z"
}
}