{"id":"CVE-2026-54257","aliases":["EUVD-2026-38539","GHSA-q6m5-f73j-m9mc"],"status":"published","title":"Electron: Buffer performs incorrect byte length calculations resulting in heap buffer under/overflow","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.","severity":{"version":"4.0","score":9.3,"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","level":"critical","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-12","score":0.00428,"percentile":0.37516,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-120"],"published":"2026-06-15T20:20:24Z","modified":"2026-11-11T02:48:52Z","fixes":[{"ecosystem":"npm","package":"electron","fixed_in":["42.3.3"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"npm","package":"electron","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"42.3.1"},{"fixed":"42.3.3"}]}]},{"source":"osv","ecosystem":"npm","package":"electron","ranges":[{"type":"SEMVER","events":[{"introduced":"42.3.1"},{"fixed":"42.3.3"}]}]}],"products":[{"vendor":"electron","product":"electron"}],"references":[{"url":"https://github.com/electron/electron/security/advisories/GHSA-q6m5-f73j-m9mc","tags":["x_refsource_CONFIRM","advisory","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-54257","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-q6m5-f73j-m9mc"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/54xxx/CVE-2026-54257.json","tags":["advisory"]},{"url":"https://github.com/electron/electron","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2026-54257","title":"Electron: Buffer performs incorrect byte length calculations resulting in heap buffer under/overflow","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.","status":"published","published":"2026-06-23T17:08:31.786Z","modified":"2026-06-23T17:47:47.594Z","cvss":[{"version":"4.0","score":9.3,"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","level":"critical","assessor":"cna"}],"cwes":["CWE-120"],"updated_at":"2026-11-02T13:37:58.613221Z"}],"euvd":[{"id":"EUVD-2026-38539","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.","status":"published","published":"2026-06-23T17:08:31Z","modified":"2026-06-23T17:47:47Z","cvss":[{"version":"4.0","score":9.3,"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","level":"critical"}],"updated_at":"2026-11-02T18:20:31.51905Z"}],"ghsa":[{"id":"GHSA-q6m5-f73j-m9mc","title":"Electron: Buffer performs incorrect byte length calculations resulting in heap buffer under/overflow","description":"### Impact\nMost apps will crash and some may perform incorrect buffer allocations in the Node.js `Buffer` API resulting in unexpected truncation or allocation.\n\n### Workarounds\nNo workarounds. Do not use these impacted Electron releases\n\n### Fixed Versions\n* `42.3.3`\n\n### For more information\nIf you have any questions or comments about this advisory, email us at [security@electronjs.org](mailto:security@electronjs.org)","status":"published","published":"2026-06-15T20:20:24Z","modified":"2026-07-20T21:02:01Z","cvss":[{"version":"4.0","score":9.3,"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","level":"critical"}],"cwes":["CWE-120"],"updated_at":"2026-11-02T14:40:47.245721Z"}],"nvd":[{"id":"CVE-2026-54257","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.","status":"published","published":"2026-06-23T18:18:07.803Z","modified":"2026-06-25T20:18:11.603Z","cvss":[{"version":"4.0","score":9.3,"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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"critical","assessor":"secondary"}],"cwes":["CWE-120"],"updated_at":"2026-11-02T14:12:25.288279Z"}],"osv":[{"id":"CVE-2026-54257","title":"Electron: Buffer performs incorrect byte length calculations resulting in heap buffer under/overflow","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.","status":"published","published":"2026-06-23T17:08:31.786Z","modified":"2026-11-11T02:48:52.212770467Z","cvss":[{"version":"4.0","score":9.3,"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","level":"critical"}],"cwes":["CWE-120"],"updated_at":"2026-11-11T03:22:00.901153Z"},{"id":"GHSA-q6m5-f73j-m9mc","title":"Electron: Buffer performs incorrect byte length calculations resulting in heap buffer under/overflow","description":"### Impact\nMost apps will crash and some may perform incorrect buffer allocations in the Node.js `Buffer` API resulting in unexpected truncation or allocation.\n\n### Workarounds\nNo workarounds. Do not use these impacted Electron releases\n\n### Fixed Versions\n* `42.3.3`\n\n### For more information\nIf you have any questions or comments about this advisory, email us at [security@electronjs.org](mailto:security@electronjs.org)","status":"published","published":"2026-06-15T20:20:24Z","modified":"2026-07-20T21:15:24.427733273Z","cvss":[{"version":"4.0","score":9.3,"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","level":"critical"}],"cwes":["CWE-120"],"updated_at":"2026-11-02T15:46:54.055966Z"}]}}