{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-21509", "assignerOrgId": "f38d906d-7342-40ea-92c1-6c4a2c6478c8", "state": "PUBLISHED", "assignerShortName": "microsoft", "dateReserved": "2025-12-30T18:10:54.844Z", "datePublished": "2026-01-26T17:06:35.512Z", "dateUpdated": "2026-04-01T13:49:28.047Z"}, "containers": {"cna": {"title": "Microsoft Office Security Feature Bypass Vulnerability", "datePublic": "2026-01-26T16:00:00.000Z", "cpeApplicability": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:a:microsoft:office_2019:*:*:*:*:*:*:*:*", "versionStartIncluding": "19.0.0", "versionEndExcluding": "16.0.10417.20095"}, {"vulnerable": true, "criteria": "cpe:2.3:a:microsoft:365_apps:*:*:*:*:enterprise:*:*:*", "versionStartIncluding": "16.0.1", "versionEndExcluding": "https://aka.ms/OfficeSecurityReleases"}, {"vulnerable": true, "criteria": "cpe:2.3:a:microsoft:office_2021:*:*:*:*:long_term_servicing_channel:*:*:*", "versionStartIncluding": "16.0.1", "versionEndExcluding": "https://aka.ms/OfficeSecurityReleases"}, {"vulnerable": true, "criteria": "cpe:2.3:a:microsoft:office_2024:*:*:*:*:long_term_servicing_channel:*:*:*", "versionStartIncluding": "16.0.0", "versionEndExcluding": "https://aka.ms/OfficeSecurityReleases"}, {"vulnerable": true, "criteria": "cpe:2.3:a:microsoft:office_2016:*:*:*:*:*:*:x86:*", "versionStartIncluding": "16.0.0", "versionEndExcluding": "16.0.5539.1001"}]}]}], "affected": [{"vendor": "Microsoft", "product": "Microsoft 365 Apps for Enterprise", "platforms": ["32-bit Systems", "x64-based Systems"], "versions": [{"version": "16.0.1", "lessThan": "https://aka.ms/OfficeSecurityReleases", "versionType": "custom", "status": "affected"}]}, {"vendor": "Microsoft", "product": "Microsoft Office 2016", "platforms": ["32-bit Systems", "x64-based Systems"], "versions": [{"version": "16.0.0", "lessThan": "16.0.5539.1001", "versionType": "custom", "status": "affected"}]}, {"vendor": "Microsoft", "product": "Microsoft Office 2019", "platforms": ["32-bit Systems", "x64-based Systems"], "versions": [{"version": "19.0.0", "lessThan": "16.0.10417.20095", "versionType": "custom", "status": "affected"}]}, {"vendor": "Microsoft", "product": "Microsoft Office LTSC 2021", "platforms": ["32-bit Systems", "x64-based Systems"], "versions": [{"version": "16.0.1", "lessThan": "https://aka.ms/OfficeSecurityReleases", "versionType": "custom", "status": "affected"}]}, {"vendor": "Microsoft", "product": "Microsoft Office LTSC 2024", "platforms": ["32-bit Systems", "x64-based Systems"], "versions": [{"version": "16.0.0", "lessThan": "https://aka.ms/OfficeSecurityReleases", "versionType": "custom", "status": "affected"}]}], "descriptions": [{"value": "Reliance on untrusted inputs in a security decision in Microsoft Office allows an unauthorized attacker to bypass a security feature locally.", "lang": "en-US"}], "problemTypes": [{"descriptions": [{"description": "CWE-807: Reliance on Untrusted Inputs in a Security Decision", "lang": "en-US", "type": "CWE", "cweId": "CWE-807"}]}], "providerMetadata": {"orgId": "f38d906d-7342-40ea-92c1-6c4a2c6478c8", "shortName": "microsoft", "dateUpdated": "2026-04-01T13:49:28.047Z"}, "references": [{"name": "Microsoft Office Security Feature Bypass Vulnerability", "tags": ["vendor-advisory", "patch"], "url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21509"}], "metrics": [{"format": "CVSS", "scenarios": [{"lang": "en-US", "value": "GENERAL"}], "cvssV3_1": {"version": "3.1", "baseSeverity": "HIGH", "baseScore": 7.8, "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:F/RL:O/RC:C"}}]}, "adp": [{"references": [{"url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-21509", "tags": ["government-resource"]}], "metrics": [{"other": {"type": "ssvc", "content": {"timestamp": "2026-01-27T13:34:19.867845Z", "id": "CVE-2026-21509", "options": [{"Exploitation": "active"}, {"Automatable": "no"}, {"Technical Impact": "total"}], "role": "CISA Coordinator", "version": "2.0.3"}}}, {"other": {"type": "kev", "content": {"dateAdded": "2026-01-26", "reference": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-21509"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-01-27T13:34:26.498Z"}}, {"providerMetadata": {"orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2026-02-10T14:57:48.648Z"}, "references": [{"url": "https://www.vicarius.io/vsociety/posts/cve-2026-21509-detection-script-microsoft-office-security-feature-bypass-vulnerability"}, {"url": "https://www.vicarius.io/vsociety/posts/cve-2026-21509-mitigation-script-microsoft-office-security-feature-bypass-vulnerability"}], "title": "CVE Program Container", "x_generator": {"engine": "ADPogram 0.0.1"}}]}}