Cyber Resilience

CVE-2026-34767

Medium

Published: 04 April 2026

Published
04 April 2026
Modified
09 April 2026
KEV Added
Patch
CVSS Score v3.1 5.9 CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:H/A:N
EPSS Score 0.0021 11.4th percentile
Risk Priority 35 floored blend · peak EPSS

Summary

CVE-2026-34767 is a medium-severity Injection (CWE-74) vulnerability in Electronjs Electron. Its CVSS base score is 5.9 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Disable or Modify Tools (T1685); ranked at the 11.4th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability details

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…

more

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.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1685 Disable or Modify Tools Defense Impairment
Adversaries may disable, degrade, or tamper with security tools or applications (e.
Why these techniques?

Header injection enables modification of security headers (CSP, CORS, cookies) to impair defenses in affected Electron apps.

Confidence: MEDIUM · MITRE ATT&CK Enterprise v19.0

Affected Assets

electronjs
electron
≤ 38.8.6 · 39.0.0 — 39.8.3 · 40.0.0 — 40.8.3

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-74

Developer assessments and testing (including injection-focused techniques) identify improper neutralization of special elements, and the verifiable flaw remediation corrects them pre-deployment.

addresses: CWE-74

Identifies indicators of injection attacks (command, SQL, LDAP, etc.) via anomaly and attack monitoring.

References