Is CVE-2026-34777 in the CISA KEV catalog?

No. CVE-2026-34777 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2026-34777?

CVE-2026-34777 has a CVSS v3 base score of 5.4 (MEDIUM).

What is the EPSS score for CVE-2026-34777?

CVE-2026-34777 has an EPSS score of 0.12% (2th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2026-34777?

Upgrade electron to 40.8.1 or later.

CVE & CISA-KEV Catalog

CVE-2026-34777

MEDIUM

5.4

CVSS v3

NVD

Description

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, when an iframe requests fullscreen, pointerLock, keyboardLock, openExternal, or media permissions, the origin passed to session.setPermissionRequestHandler() was the top-level page's origin rather than the requesting iframe's origin. Apps that grant permissions based on the origin parameter or webContents.getURL() may inadvertently grant permissions to embedded third-party content. The correct requesting URL remains available via details.requestingUrl. Apps that already check details.requestingUrl are not affected. This issue has been patched in versions 38.8.6, 39.8.1, 40.8.1, and 41.0.0.

CWE-346

How to fix

Remediation Available

electronNVD

Affected:>= 40.0.0, < 40.8.1Fixed in:40.8.1CVE-2026-34777derived from NVD

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredNone

User InteractionRequired

ScopeUnchanged

Impact

ConfidentialityLow

IntegrityLow

AvailabilityNone

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N

Exploit Intelligence

0.12%probability of exploitation in 30 days

2ndpercentile

Low risk: more likely to be exploited than 2% of all known CVEs.

References

Vendor Advisory1

github.com

Related Vulnerabilities

Other CWE-346 vulnerabilities, ordered by exploit likelihood. View all

CVE	Severity	CVSS	EPSS	Exploited	Fix
CVE-2009-1185	High	7.2	82%	-	Fix
CVE-2025-34291	High	8.8	79%	KEV	-
CVE-2020-16952	High	8.6	71%	-	-
CVE-2023-29711	Critical	9.8	70%	-	-
CVE-2015-4495	High	8.8	70%	KEV	Fix
CVE-2024-23898	High	8.8	67%	-	Fix

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-04-20.