CVE-2026-34767: Electron: HTTP Response Header Injection in custom protocol handlers and webRequest
Noroxi assessment
Priority: Monitor (action score 26/100)
- The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
- Probability of exploitation in the next 30 days: 0.21% (FIRST EPSS).
- Anyone who can reach it over the internet can trigger it. No account or password is required. A user must open a link or visit a page. No special conditions are required; it is repeatable.
- Fixed version: electron (npm) 39.8.3, 40.8.3, 41.0.3.
Low priority for now. Upgrade to electron (npm) 39.8.3, 40.8.3, 41.0.3 or later.
Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it
Primary sources: NVD · CVE.org · FIRST EPSS
Electron is a framework for writing cross-platform desktop applications using JavaScript, HTML and CSS. Prior to versions 38.8.6, 39.8.3, 40.8.3, and 41.0.3, 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. This issue has been patched in versions 38.8.6, 39.8.3, 40.8.3, and 41.0.3.
- Published
- Apr 3, 2026
- Updated
- Jul 24, 2026
- EPSS
- 0.2% · 11th percentile
- CWE
- CWE-74
Report tools
Action score
26
Monitor
Low priority for now.
- CVSS
- 26 / 40 · 6.5 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.2%
CISA SSVC decision
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- 6.5
- CNA · GitHub_M
- 5.9
- 0.6 point gap
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:H/A:N
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Get told when this record changes
- Not in KEV: no record of exploitation in the wild
- No public exploit code on record
- A fix has been released
If any of these changes, we'll tell you in the daily email digest.
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Noroxi analysis
What does it mean in your environment?
The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.
We use this product, ask for helpAffected systems
Is your version affected?
Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.
| Vendor | Product | CPE |
|---|---|---|
| electronjs | electron | cpe:2.3:a:electronjs:electron |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- electronjs electronbefore 38.8.6
- electronjs electron39.0.0 and later · before 39.8.3
- electronjs electron40.0.0 and later · before 40.8.3
- electronjs electron41.0.0 and later · before 41.0.3
Versions reported by the vendor
Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.
electron electron
- < 38.8.6, >= 39.0.0-alpha.1, < 39.8.3, >= 40.0.0-alpha.1, < 40.8.3, >= 41.0.0-alpha.1, < 41.0.3affected
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| npm | electron | from 39.0.0-alpha.1 · before 39.8.3 | 39.8.3 |
| npm | electron | from 40.0.0-alpha.1 · before 40.8.3 | 40.8.3 |
| npm | electron | from 41.0.0-alpha.1 · before 41.0.3 | 41.0.3 |
| npm | electron | before 38.8.6 | 38.8.6 |
Same product
electronjs: all recordsOther highest-scoring records for the same primary product.
- CVE-2017-16151Based on details posted by the ElectronJS team; A remote code execution vulnerability has been discovered in Google Chromium that affects al40Plan
- CVE-2026-102676Electron: <webview> can enable Node.js integration in Web Workers despite embedder restrictions39Monitor
- CVE-2026-34775Electron: nodeIntegrationInWorker not correctly scoped in shared renderer processes39Monitor
Published before and after this one in the same product
- ← EarlierCVE-2023-44402Dec 1, 2023 · ASAR Integrity bypass via filetype confusion in electron28Monitor
- ← EarlierCVE-2026-34766Apr 3, 2026 · Electron: USB device selection not validated against filtered device list21Monitor
- Later →CVE-2026-34768Apr 3, 2026 · Electron: Unquoted executable path in app.setLoginItemSettings on Windows31Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| npm:electron | 38.8.6 | Package registry (OSV) |
| npm:electron | 39.8.3 | Package registry (OSV) |
| npm:electron | 40.8.3 | Package registry (OSV) |
| npm:electron | 41.0.3 | Package registry (OSV) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- No account or password is required.
- A user must open a link or visit a page.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- none
- Integrity
- high · data or configuration can be modified
- Availability
- none
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- Required
- Scope
- Unchanged
- Confidentiality impact
- None
- Integrity impact
- High
- Availability impact
- None
Weakness class (CWE)
CWE-74 · Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N
nvd-primary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Attack patterns (CAPEC)
- Buffer Overflow via Environment VariablesCAPEC-10likelihood: High · High
- Server Side Include (SSI) InjectionCAPEC-101likelihood: High · High
- HTTP Request SplittingCAPEC-105likelihood: Medium · High
- Command Line Execution through SQL InjectionCAPEC-108likelihood: Low · Very High
- Double EncodingCAPEC-120likelihood: Low · Medium
- Subverting Environment Variable ValuesCAPEC-13likelihood: High · Very High
- Format String InjectionCAPEC-135likelihood: High · High
- Client-side Injection-induced Buffer OverflowCAPEC-14likelihood: Medium · High
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Vendor advisories and official records. Exploit/PoC links are deliberately left out.