{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-20955", "assignerOrgId": "f38d906d-7342-40ea-92c1-6c4a2c6478c8", "state": "PUBLISHED", "assignerShortName": "microsoft", "dateReserved": "2025-12-04T20:04:16.340Z", "datePublished": "2026-01-13T17:56:47.973Z", "dateUpdated": "2026-04-01T13:48:57.702Z"}, "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:office_2021:*:*:*:*:ltsc:*:*:*", "versionStartIncluding": "16.0.0.0", "versionEndExcluding": "16.0.10417.20083"}, {"vulnerable": true, "criteria": "cpe:2.3:a:microsoft:office_2019:*:*:*:*:*:*:*:*", "versionStartIncluding": "19.0.0", "versionEndExcluding": "https://aka.ms/OfficeSecurityReleases"}, {"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 2019", "platforms": ["32-bit Systems", "x64-based Systems"], "versions": [{"version": "19.0.0", "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"}]}, {"vendor": "Microsoft", "product": "Office Online Server", "versions": [{"version": "16.0.0.0", "lessThan": "16.0.10417.20083", "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": "2026-04-01T13:48:57.702Z"}, "references": [{"name": "Microsoft Excel Remote Code Execution Vulnerability", "tags": ["vendor-advisory", "patch"], "url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20955"}], "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-2026-20955", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "total"}], "version": "2.0.3", "timestamp": "2026-01-14T04:56:20.272125Z"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-02-26T15:04:26.450Z"}}]}}

{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-20955", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "total"}], "version": "2.0.3", "timestamp": "2026-01-14T04:56:20.272125Z"}}}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-01-13T20:23:44.121Z"}}], "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 2019", "versions": [{"status": "affected", "version": "19.0.0", "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"}]}, {"vendor": "Microsoft", "product": "Office Online Server", "versions": [{"status": "affected", "version": "16.0.0.0", "lessThan": "16.0.10417.20083", "versionType": "custom"}]}], "datePublic": "2026-01-13T16:00:00.000Z", "references": [{"url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20955", "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:office_2021:*:*:*:*:ltsc:*:*:*", "vulnerable": true, "versionEndExcluding": "16.0.10417.20083", "versionStartIncluding": "16.0.0.0"}, {"criteria": "cpe:2.3:a:microsoft:office_2019:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "https://aka.ms/OfficeSecurityReleases", "versionStartIncluding": "19.0.0"}, {"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": "2026-04-01T13:48:57.702Z"}}}, "cveMetadata": {"cveId": "CVE-2026-20955", "state": "PUBLISHED", "dateUpdated": "2026-04-01T13:48:57.702Z", "dateReserved": "2025-12-04T20:04:16.340Z", "assignerOrgId": "f38d906d-7342-40ea-92c1-6c4a2c6478c8", "datePublished": "2026-01-13T17:56:47.973Z", "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:2019:*:*:*:*:*:x64:*", "matchCriteriaId": "CF5DDD09-902E-4881-98D0-CB896333B4AA", "vulnerable": true}, {"criteria": "cpe:2.3:a:microsoft:office:2019:*:*:*:*:*:x86:*", "matchCriteriaId": "26A3B226-5D7C-4556-9350-5222DC8EFC2C", "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}, {"criteria": "cpe:2.3:a:microsoft:office_online_server:*:*:*:*:*:*:*:*", "matchCriteriaId": "08A33F86-5F76-4BF6-8C56-678924FDB333", "versionEndExcluding": "16.0.10417.20083", "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-2026-20955", "lastModified": "2026-01-14T19:49:54.657", "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": "2026-01-13T18:16:23.307", "references": [{"source": "secure@microsoft.com", "tags": ["Vendor Advisory"], "url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20955"}], "sourceIdentifier": "secure@microsoft.com", "vulnStatus": "Analyzed", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-822"}], "source": "secure@microsoft.com", "type": "Primary"}]}

{}

{"analysis": {"en": {"generated_at": "2026-04-16T08:14:58.250155+00:00", "value": {"mitigation_remediation": ["Install the latest Microsoft Office security updates via Windows Update or the Office update channel.", "Ensure that all Office applications for the affected products are running the most recent patch level.", "If the patch is not yet available, restrict users from opening unknown or untrusted Excel files, use macro security settings set to disable or display prompts, and consider applying software restriction policies or endpoint protection to block execution of malicious content."], "summary": {"action": "Apply Patch", "impact": "Local Code Execution"}, "threat_synthesis": {"affected_systems": "Affected suppliers include Microsoft 365 Apps for Enterprise, Microsoft Office 2019, Microsoft Office LTSC 2021, Microsoft Office LTSC 2024, Microsoft Office LTSC for Mac 2021, Microsoft Office LTSC for Mac 2024, and Office Online Server. Version details are not listed, so the vulnerability applies to the current releases of these products.", "description_and_impact": "Untrusted pointer dereference in Microsoft Office Excel allows an attacker who can supply a crafted spreadsheet to execute arbitrary code on the victim\u2019s machine. The weakness is identified as CWE-822 and carries a CVSS score of 7.8, indicating a high risk to confidentiality and integrity when an authorized user opens a malicious file.", "risk_and_exploitability": "The vulnerability is local in nature; an attacker must provide a malicious Excel file that a user opens or processes. Because it requires local user interaction, the EPSS score of less than 1% reflects a low probability of currently observed exploitation, and the vulnerability is not present in the CISA KEV catalog. Nevertheless, the high CVSS score means that once a user opens a weaponized file, the attacker could achieve full code execution on that system. The likelihood of exploitation is dominated by user behavior and trust of file sources."}}}}, "created": "2026-04-16T08:15:29.662954+00:00", "updated": "2026-04-16T08:15:29.662966+00:00", "vendors": []}