CVE-2026-54257
CVE-2026-54257 is a critical-severity vulnerability with a CVSS 4.0 base score of 9.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-120.
Key facts
- Severity: Critical (CVSS 4.0 base score 9.3)
- EPSS exploit prediction: 0% (17th percentile)
- Actively exploited: Not listed in CISA KEV
- EU (EUVD) id: EUVD-2026-38539
- Weakness: CWE-120
- Published:
- Last modified:
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.
Frequently asked questions
- What is CVE-2026-54257?
- 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.
- How severe is CVE-2026-54257?
- CVE-2026-54257 has a CVSS 4.0 base score of 9.3, rated critical severity.
- Is CVE-2026-54257 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (17th percentile), an estimate of the probability of exploitation in the next 30 days.
- How do I fix CVE-2026-54257?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
- Does CVE-2026-54257 have an EU (EUVD) identifier?
- Yes. CVE-2026-54257 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-38539.
- When was CVE-2026-54257 published?
- CVE-2026-54257 was published on 2026-06-23 and last updated on 2026-06-25.
References
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