CVE-2026-34773 | Electron: Registry key path injection in app.setAsDefaultProtocolClient on Windows

Electron is a framework for writing cross-platform desktop applications using JavaScript, HTML and CSS. Prior to versions 38.8.6, 39.8.1, 40.8.1, and 41.0.0, on Windows, app.setAsDefaultProtocolClient(protocol) did not validate the protocol name before writing to the registry. Apps that pass untrusted input as the protocol name may allow an attacker to write to arbitrary subkeys under HKCU\Software\Classes\, potentially hijacking existing protocol handlers. Apps are only affected if they call app.setAsDefaultProtocolClient() with a protocol name derived from external or untrusted input. Apps that use a hardcoded protocol name are not affected. This issue has been patched in versions 38.8.6, 39.8.1, 40.8.1, and 41.0.0.

Published: 2026-04-04 Last update: 2026-04-22 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-34773 is rated Low Risk (24.2/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.24%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-34773

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.03% 0.24% +0.21%
2 2026-04-04 — 0.03% —

Full EPSS history (2 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-34773

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
4.7 3.1 MEDIUM
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:N Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:N)
Service keeps running; no real outage angle.
 1.0 3.6 [email protected]
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:N)
Service keeps running; no real outage angle.
 3.9 3.6 [email protected]

Weakness enumeration for CVE-2026-34773

GitHub Security Advisory for CVE-2026-34773

GHSA-mwmh-mq4g-g6gr · Severity: medium · Ecosystem: npm — Electron: Registry key path injection in app.setAsDefaultProtocolClient on Windows

OS Trackers for CVE-2026-34773

vendor priority summary link
redhat medium — https://access.redhat.com/security/cve/CVE-2026-34773

Affected software / configurations for CVE-2026-34773

Vendor Product Version Raw CPE
electronjs electron < 38.8.6 cpe:2.3:a:electronjs:electron:*:*:*:*:*:node.js:*:*
electronjs electron >= 39.0.0, < 39.8.1 cpe:2.3:a:electronjs:electron:*:*:*:*:*:node.js:*:*
electronjs electron >= 40.0.0, < 40.8.1 cpe:2.3:a:electronjs:electron:*:*:*:*:*:node.js:*:*
electronjs electron 41.0.0 cpe:2.3:a:electronjs:electron:41.0.0:alpha1:*:*:*:node.js:*:*
electronjs electron 41.0.0 cpe:2.3:a:electronjs:electron:41.0.0:alpha2:*:*:*:node.js:*:*
electronjs electron 41.0.0 cpe:2.3:a:electronjs:electron:41.0.0:alpha3:*:*:*:node.js:*:*
electronjs electron 41.0.0 cpe:2.3:a:electronjs:electron:41.0.0:alpha4:*:*:*:node.js:*:*
electronjs electron 41.0.0 cpe:2.3:a:electronjs:electron:41.0.0:alpha5:*:*:*:node.js:*:*
electronjs electron 41.0.0 cpe:2.3:a:electronjs:electron:41.0.0:alpha6:*:*:*:node.js:*:*
electronjs electron 41.0.0 cpe:2.3:a:electronjs:electron:41.0.0:beta1:*:*:*:node.js:*:*
electronjs electron 41.0.0 cpe:2.3:a:electronjs:electron:41.0.0:beta2:*:*:*:node.js:*:*
electronjs electron 41.0.0 cpe:2.3:a:electronjs:electron:41.0.0:beta3:*:*:*:node.js:*:*
electronjs electron 41.0.0 cpe:2.3:a:electronjs:electron:41.0.0:beta4:*:*:*:node.js:*:*
electronjs electron 41.0.0 cpe:2.3:a:electronjs:electron:41.0.0:beta5:*:*:*:node.js:*:*
electronjs electron 41.0.0 cpe:2.3:a:electronjs:electron:41.0.0:beta6:*:*:*:node.js:*:*
electronjs electron 41.0.0 cpe:2.3:a:electronjs:electron:41.0.0:beta7:*:*:*:node.js:*:*
electronjs electron 41.0.0 cpe:2.3:a:electronjs:electron:41.0.0:beta8:*:*:*:node.js:*:*

References for CVE-2026-34773

cvelogic Threat Intelligence