{"id":"CVE-2026-55949","aliases":["EUVD-2026-44231","GHSA-g26f-g9f2-wqvr"],"status":"published","title":"Microsoft Excel Remote Code Execution Vulnerability","description":"Use of uninitialized resource in Microsoft Office Excel allows an unauthorized attacker to execute code locally.","severity":{"version":"3.1","score":7.8,"vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-08","score":0.00466,"percentile":0.40631,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-908"],"published":"2026-07-14T17:09:12Z","modified":"2026-11-01T17:36:43Z","products":[{"vendor":"microsoft","product":"365_apps"},{"vendor":"microsoft","product":"excel"},{"vendor":"microsoft","product":"microsoft 365 apps for enterprise"},{"vendor":"microsoft","product":"microsoft excel 2016"},{"vendor":"microsoft","product":"microsoft office 2019"},{"vendor":"microsoft","product":"microsoft office 365 for mac"},{"vendor":"microsoft","product":"microsoft office ltsc 2021"},{"vendor":"microsoft","product":"microsoft office ltsc 2024"},{"vendor":"microsoft","product":"microsoft office ltsc for mac 2021"},{"vendor":"microsoft","product":"microsoft office ltsc for mac 2024"},{"vendor":"microsoft","product":"microsoft_365"},{"vendor":"microsoft","product":"office online server"},{"vendor":"microsoft","product":"office_2019"},{"vendor":"microsoft","product":"office_2021"},{"vendor":"microsoft","product":"office_2024"},{"vendor":"microsoft","product":"office_online_server"}],"references":[{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-55949","tags":["vendor-advisory","patch","Vendor Advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-55949"},{"url":"https://github.com/advisories/GHSA-g26f-g9f2-wqvr"}],"sources":{"cve":[{"id":"CVE-2026-55949","title":"Microsoft Excel Remote Code Execution Vulnerability","description":"Use of uninitialized resource in Microsoft Office Excel allows an unauthorized attacker to execute code locally.","status":"published","published":"2026-07-14T17:09:12.118Z","modified":"2026-11-01T17:36:43.9Z","cvss":[{"version":"3.1","score":7.8,"vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C","level":"high","assessor":"cna"}],"cwes":["CWE-908"],"updated_at":"2026-11-02T14:20:11.925815Z"}],"euvd":[{"id":"EUVD-2026-44231","description":"Use of uninitialized resource in Microsoft Office Excel allows an unauthorized attacker to execute code locally.","status":"published","published":"2026-07-14T17:09:12Z","modified":"2026-11-01T17:36:43Z","cvss":[{"version":"3.1","score":7.8,"vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C","level":"high"}],"updated_at":"2026-11-02T16:58:46.970263Z"}],"ghsa":[{"id":"GHSA-g26f-g9f2-wqvr","title":"Use of uninitialized resource in Microsoft Office Excel allows an unauthorized attacker to...","description":"Use of uninitialized resource in Microsoft Office Excel allows an unauthorized attacker to execute code locally.","status":"published","published":"2026-07-14T18:32:36Z","modified":"2026-07-14T18:32:42Z","cvss":[{"version":"3.1","score":7.8,"vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","level":"high"}],"cwes":["CWE-908"],"updated_at":"2026-11-02T15:09:30.715875Z"}],"nvd":[{"id":"CVE-2026-55949","description":"Use of uninitialized resource in Microsoft Office Excel allows an unauthorized attacker to execute code locally.","status":"published","published":"2026-07-14T18:18:22.32Z","modified":"2026-07-15T16:22:11.707Z","cvss":[{"version":"3.1","score":7.8,"vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","level":"high","assessor":"secondary"}],"cwes":["CWE-908"],"updated_at":"2026-11-02T14:12:29.489525Z"}]}}