Vulnerability · Published Jun 23, 2026 · Assigned by GitHub_M

CVE-2026-54257Electron: Buffer performs incorrect byte length calculations resulting in heap buffer under/overflow

Critical 9.3

In plain English

A critical-severity buffer overflow in electron from electron. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 37% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 4.0)9.3Critical

Exploit odds (30 days)0.4%top 62.8% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

Electron is a framework for writing cross-platform desktop applications using JavaScript, HTML and CSS. From 42.3.1 until 42.3.3, Buffer performs incorrect byte length calculations resulting in heap buffer under/overflow. Most apps will crash and some may perform incorrect buffer allocations in the Node.js Buffer API resulting in unexpected truncation or allocation. This vulnerability is fixed in 42.3.3.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
npm	electron	42.3.3	GHSA-q6m5-f73j-m9mc

Affected products (as reported)

Vendor	Product	Versions
electron	electron	>= 42.3.1, < 42.3.3

Weakness: CWE-120 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

References

https://github.com/electron/electron/security/advisories/GHSA-q6m5-f73j-m9mc x_refsource_CONFIRM