{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-20956", "assignerOrgId": "f38d906d-7342-40ea-92c1-6c4a2c6478c8", "state": "PUBLISHED", "assignerShortName": "microsoft", "dateReserved": "2025-12-04T20:04:16.340Z", "datePublished": "2026-01-13T17:56:48.553Z", "dateUpdated": "2026-04-01T13:48:58.355Z"}, "containers": {"cna": {"title": "Microsoft Excel Remote Code Execution Vulnerability", "datePublic": "2026-01-13T16:00:00.000Z", "cpeApplicability": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"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_macos_2021:*:*:*:*:*:long_term_servicing_channel:*:*", "versionStartIncluding": "16.0.1", "versionEndExcluding": "16.105.26011018"}, {"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_macos_2024:*:*:*:*:*:long_term_servicing_channel:*:*", "versionStartIncluding": "16.0.0", "versionEndExcluding": "16.105.26011018"}]}]}], "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 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"}]}, {"vendor": "Microsoft", "product": "Microsoft Office LTSC for Mac 2021", "versions": [{"version": "16.0.1", "lessThan": "16.105.26011018", "versionType": "custom", "status": "affected"}]}, {"vendor": "Microsoft", "product": "Microsoft Office LTSC for Mac 2024", "versions": [{"version": "16.0.0", "lessThan": "16.105.26011018", "versionType": "custom", "status": "affected"}]}], "descriptions": [{"value": "Untrusted pointer dereference in Microsoft Office Excel allows an unauthorized attacker to execute code locally.", "lang": "en-US"}], "problemTypes": [{"descriptions": [{"description": "CWE-822: Untrusted Pointer Dereference", "lang": "en-US", "type": "CWE", "cweId": "CWE-822"}]}], "providerMetadata": {"orgId": "f38d906d-7342-40ea-92c1-6c4a2c6478c8", "shortName": "microsoft", "dateUpdated": "2026-04-01T13:48:58.355Z"}, "references": [{"name": "Microsoft Excel Remote Code Execution Vulnerability", "tags": ["vendor-advisory", "patch"], "url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20956"}], "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:U/RL:O/RC:C"}}]}, "adp": [{"metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-20956", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "total"}], "version": "2.0.3", "timestamp": "2026-01-14T04:56:24.468633Z"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-02-26T15:04:26.131Z"}}]}}

{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-20956", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "total"}], "version": "2.0.3", "timestamp": "2026-01-14T04:56:24.468633Z"}}}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-01-13T20:23:20.616Z"}}], "cna": {"title": "Microsoft Excel Remote Code Execution Vulnerability", "metrics": [{"format": "CVSS", "cvssV3_1": {"version": "3.1", "baseScore": 7.8, "baseSeverity": "HIGH", "vectorString": "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"}, "scenarios": [{"lang": "en-US", "value": "GENERAL"}]}], "affected": [{"vendor": "Microsoft", "product": "Microsoft 365 Apps for Enterprise", "versions": [{"status": "affected", "version": "16.0.1", "lessThan": "https://aka.ms/OfficeSecurityReleases", "versionType": "custom"}], "platforms": ["32-bit Systems", "x64-based Systems"]}, {"vendor": "Microsoft", "product": "Microsoft Office LTSC 2021", "versions": [{"status": "affected", "version": "16.0.1", "lessThan": "https://aka.ms/OfficeSecurityReleases", "versionType": "custom"}], "platforms": ["32-bit Systems", "x64-based Systems"]}, {"vendor": "Microsoft", "product": "Microsoft Office LTSC 2024", "versions": [{"status": "affected", "version": "16.0.0", "lessThan": "https://aka.ms/OfficeSecurityReleases", "versionType": "custom"}], "platforms": ["32-bit Systems", "x64-based Systems"]}, {"vendor": "Microsoft", "product": "Microsoft Office LTSC for Mac 2021", "versions": [{"status": "affected", "version": "16.0.1", "lessThan": "16.105.26011018", "versionType": "custom"}]}, {"vendor": "Microsoft", "product": "Microsoft Office LTSC for Mac 2024", "versions": [{"status": "affected", "version": "16.0.0", "lessThan": "16.105.26011018", "versionType": "custom"}]}], "datePublic": "2026-01-13T16:00:00.000Z", "references": [{"url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20956", "name": "Microsoft Excel Remote Code Execution Vulnerability", "tags": ["vendor-advisory", "patch"]}], "descriptions": [{"lang": "en-US", "value": "Untrusted pointer dereference in Microsoft Office Excel allows an unauthorized attacker to execute code locally."}], "problemTypes": [{"descriptions": [{"lang": "en-US", "type": "CWE", "cweId": "CWE-822", "description": "CWE-822: Untrusted Pointer Dereference"}]}], "cpeApplicability": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:a:microsoft:365_apps:*:*:*:*:enterprise:*:*:*", "vulnerable": true, "versionEndExcluding": "https://aka.ms/OfficeSecurityReleases", "versionStartIncluding": "16.0.1"}, {"criteria": "cpe:2.3:a:microsoft:office_macos_2021:*:*:*:*:*:long_term_servicing_channel:*:*", "vulnerable": true, "versionEndExcluding": "16.105.26011018", "versionStartIncluding": "16.0.1"}, {"criteria": "cpe:2.3:a:microsoft:office_2021:*:*:*:*:long_term_servicing_channel:*:*:*", "vulnerable": true, "versionEndExcluding": "https://aka.ms/OfficeSecurityReleases", "versionStartIncluding": "16.0.1"}, {"criteria": "cpe:2.3:a:microsoft:office_2024:*:*:*:*:long_term_servicing_channel:*:*:*", "vulnerable": true, "versionEndExcluding": "https://aka.ms/OfficeSecurityReleases", "versionStartIncluding": "16.0.0"}, {"criteria": "cpe:2.3:a:microsoft:office_macos_2024:*:*:*:*:*:long_term_servicing_channel:*:*", "vulnerable": true, "versionEndExcluding": "16.105.26011018", "versionStartIncluding": "16.0.0"}], "operator": "OR"}]}], "providerMetadata": {"orgId": "f38d906d-7342-40ea-92c1-6c4a2c6478c8", "shortName": "microsoft", "dateUpdated": "2026-04-01T13:48:58.355Z"}}}, "cveMetadata": {"cveId": "CVE-2026-20956", "state": "PUBLISHED", "dateUpdated": "2026-04-01T13:48:58.355Z", "dateReserved": "2025-12-04T20:04:16.340Z", "assignerOrgId": "f38d906d-7342-40ea-92c1-6c4a2c6478c8", "datePublished": "2026-01-13T17:56:48.553Z", "assignerShortName": "microsoft"}, "dataVersion": "5.2"}

{"configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:a:microsoft:365_apps:-:*:*:*:enterprise:*:x64:*", "matchCriteriaId": "3259EBFE-AE2D-48B8-BE9A-E22BBDB31378", "vulnerable": true}, {"criteria": "cpe:2.3:a:microsoft:365_apps:-:*:*:*:enterprise:*:x86:*", "matchCriteriaId": "CD25F492-9272-4836-832C-8439EBE64CCF", "vulnerable": true}, {"criteria": "cpe:2.3:a:microsoft:office_long_term_servicing_channel:2021:*:*:*:*:-:x64:*", "matchCriteriaId": "851BAC4E-9965-4F40-9A6C-B73D9004F4C1", "vulnerable": true}, {"criteria": "cpe:2.3:a:microsoft:office_long_term_servicing_channel:2021:*:*:*:*:-:x86:*", "matchCriteriaId": "23B2FA23-76F4-4D83-A718-B8D04D7EA37B", "vulnerable": true}, {"criteria": "cpe:2.3:a:microsoft:office_long_term_servicing_channel:2021:*:*:*:*:macos:*:*", "matchCriteriaId": "BF0E8112-5B6F-4E55-8E40-38ADCF6FC654", "vulnerable": true}, {"criteria": "cpe:2.3:a:microsoft:office_long_term_servicing_channel:2024:*:*:*:*:-:x64:*", "matchCriteriaId": "D31E509A-0B2E-4B41-88C4-0099E800AFE6", "vulnerable": true}, {"criteria": "cpe:2.3:a:microsoft:office_long_term_servicing_channel:2024:*:*:*:*:-:x86:*", "matchCriteriaId": "017A7041-BEF1-4E4E-AC8A-EFC6AFEB01FE", "vulnerable": true}, {"criteria": "cpe:2.3:a:microsoft:office_long_term_servicing_channel:2024:*:*:*:*:macos:*:*", "matchCriteriaId": "EF3E56B5-E6A6-4061-9380-D421E52B9199", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "Untrusted pointer dereference in Microsoft Office Excel allows an unauthorized attacker to execute code locally."}], "id": "CVE-2026-20956", "lastModified": "2026-01-14T19:48:42.527", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 7.8, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "REQUIRED", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 1.8, "impactScore": 5.9, "source": "secure@microsoft.com", "type": "Primary"}]}, "published": "2026-01-13T18:16:23.467", "references": [{"source": "secure@microsoft.com", "tags": ["Vendor Advisory"], "url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20956"}], "sourceIdentifier": "secure@microsoft.com", "vulnStatus": "Analyzed", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-822"}], "source": "secure@microsoft.com", "type": "Primary"}]}

{}

{"analysis": {"en": {"generated_at": "2026-04-16T08:14:36.619138+00:00", "value": {"mitigation_remediation": ["Apply the Microsoft Office security update that fixes CVE-2026-20956.", "Ensure all affected Office installations are updated to the latest available security update rollup.", "Configure Excel to disable macros and add\u2011ins, or run the application in Safe Mode, until the patch is applied."], "summary": {"action": "Immediate Patch", "impact": "Remote Code Execution"}, "threat_synthesis": {"affected_systems": "Microsoft 365 Apps for Enterprise, Microsoft Office LTSC 2021, Microsoft Office LTSC 2024, Microsoft Office LTSC for Mac 2021, and Microsoft Office LTSC for Mac 2024 are all affected; all current releases of these products lack the fix for CVE-2026-20956.", "description_and_impact": "The flaw is an untrusted pointer dereference in Microsoft Office Excel that allows an attacker to execute arbitrary code on the victim\u2019s machine when an Excel file containing malicious content is opened, potentially compromising confidentiality, integrity, and availability.", "risk_and_exploitability": "With a CVSS score of 7.8 and an EPSS below 1%, the vulnerability presents a moderate to high severity but a low probability of exploitation; it is not listed in the CISA KEV catalog. Attackers would require a malicious workbook or attachment that a user opens, thus the attack vector is local, through user interaction, and the vulnerability is mitigated through patching. The impact of successful exploitation would be execution of code with the privileges of the logged\u2011in user, enabling full system compromise."}}}}, "created": "2026-04-16T08:15:29.661501+00:00", "updated": "2026-04-16T08:15:29.661511+00:00", "vendors": []}