{"id":"CVE-2026-21258","aliases":["EUVD-2026-7356","GHSA-v8pc-rxff-x74j"],"status":"published","title":"Microsoft Excel Information Disclosure Vulnerability","description":"Improper input validation in Microsoft Office Excel allows an unauthorized attacker to disclose information locally.","severity":{"version":"3.1","score":5.5,"vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.00627,"percentile":0.50404,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-125","CWE-20"],"published":"2026-02-10T17:51:18Z","modified":"2026-08-19T16:25:50Z","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 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":"office"},{"vendor":"microsoft","product":"office online server"},{"vendor":"microsoft","product":"office_long_term_servicing_channel"},{"vendor":"microsoft","product":"office_online_server"}],"references":[{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21258","tags":["vendor-advisory","patch","Vendor Advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-21258"},{"url":"https://github.com/advisories/GHSA-v8pc-rxff-x74j"}],"sources":{"cve":[{"id":"CVE-2026-21258","title":"Microsoft Excel Information Disclosure Vulnerability","description":"Improper input validation in Microsoft Office Excel allows an unauthorized attacker to disclose information locally.","status":"published","published":"2026-02-10T17:51:18.057Z","modified":"2026-08-19T16:25:50.521Z","cvss":[{"version":"3.1","score":5.5,"vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C","level":"medium","assessor":"cna"}],"cwes":["CWE-20","CWE-125"],"updated_at":"2026-11-02T13:41:42.05254Z"}],"euvd":[{"id":"EUVD-2026-7356","description":"Improper input validation in Microsoft Office Excel allows an unauthorized attacker to disclose information locally.","status":"published","published":"2026-02-10T17:51:18Z","modified":"2026-08-19T16:25:50Z","cvss":[{"version":"3.1","score":5.5,"vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C","level":"medium"}],"updated_at":"2026-11-02T18:01:44.550802Z"}],"ghsa":[{"id":"GHSA-v8pc-rxff-x74j","title":"Improper input validation in Microsoft Office Excel allows an unauthorized attacker to disclose...","description":"Improper input validation in Microsoft Office Excel allows an unauthorized attacker to disclose information locally.","status":"published","published":"2026-02-10T18:30:41Z","modified":"2026-02-10T18:30:52Z","cvss":[{"version":"3.1","score":5.5,"vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N","level":"medium"}],"cwes":["CWE-20"],"updated_at":"2026-11-02T15:06:07.875228Z"}],"nvd":[{"id":"CVE-2026-21258","description":"Improper input validation in Microsoft Office Excel allows an unauthorized attacker to disclose information locally.","status":"published","published":"2026-02-10T18:16:27.637Z","modified":"2026-06-17T10:18:22.76Z","cvss":[{"version":"3.1","score":5.5,"vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N","level":"medium","assessor":"secondary"}],"cwes":["CWE-20","CWE-125"],"updated_at":"2026-11-02T14:12:05.52517Z"}]}}