CVE-2026-55121

{"id": "CVE-2026-55121", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-55121", "role": "CISA Coordinator", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "version": "2.0.3", "timestamp": "2026-07-14T17:46:06.794813Z"}}], "cvssMetricV31": [{"type": "Primary", "source": "secure@microsoft.com", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 5.5, "attackVector": "LOCAL", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H", "integrityImpact": "NONE", "userInteraction": "REQUIRED", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "NONE", "confidentialityImpact": "NONE"}, "impactScore": 3.6, "exploitabilityScore": 1.8}]}, "affected": [{"source": "secure@microsoft.com", "affectedData": [{"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 2016", "versions": [{"status": "affected", "version": "16.0.0", "lessThan": "16.0.5561.1000", "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 365 for Mac", "versions": [{"status": "affected", "version": "1.0.0", "lessThan": "16.111.26071215", "versionType": "custom"}]}, {"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": "16.111.26071215", "versionType": "custom"}]}, {"vendor": "Microsoft", "product": "Microsoft Office LTSC for Mac 2024", "versions": [{"status": "affected", "version": "16.0.0", "lessThan": "16.111.26071215", "versionType": "custom"}]}, {"vendor": "Microsoft", "product": "Microsoft SharePoint Enterprise Server 2016", "versions": [{"status": "affected", "version": "16.0.0", "lessThan": "16.0.5561.1001", "versionType": "custom"}], "platforms": ["x64-based Systems"]}, {"vendor": "Microsoft", "product": "Microsoft SharePoint Server 2019", "versions": [{"status": "affected", "version": "16.0.0", "lessThan": "16.0.10417.20175", "versionType": "custom"}], "platforms": ["x64-based Systems"]}, {"vendor": "Microsoft", "product": "Microsoft SharePoint Server Subscription Edition", "versions": [{"status": "affected", "version": "16.0.0", "lessThan": "16.0.19725.20434", "versionType": "custom"}], "platforms": ["x64-based Systems"]}]}], "published": "2026-07-14T18:18:18.347", "references": [{"url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-55121", "tags": ["Patch", "Vendor Advisory"], "source": "secure@microsoft.com"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Primary", "source": "secure@microsoft.com", "description": [{"lang": "en", "value": "CWE-125"}]}], "descriptions": [{"lang": "en", "value": "Out-of-bounds read in Microsoft Office allows an unauthorized attacker to disclose information locally."}], "lastModified": "2026-07-15T20:09:38.320", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:a:microsoft:365_apps:-:*:*:*:enterprise:*:x64:*", "vulnerable": true, "matchCriteriaId": "3259EBFE-AE2D-48B8-BE9A-E22BBDB31378"}, {"criteria": "cpe:2.3:a:microsoft:365_apps:-:*:*:*:enterprise:*:x86:*", "vulnerable": true, "matchCriteriaId": "CD25F492-9272-4836-832C-8439EBE64CCF"}, {"criteria": "cpe:2.3:a:microsoft:microsoft_365:-:*:*:*:*:macos:*:*", "vulnerable": true, "matchCriteriaId": "12418BDE-FA2E-4BBF-8E47-45C505399898"}, {"criteria": "cpe:2.3:a:microsoft:office_2016:-:*:*:*:-:*:x64:*", "vulnerable": true, "matchCriteriaId": "45A9ECE7-F173-47AB-A420-0B6F64A04D21"}, {"criteria": "cpe:2.3:a:microsoft:office_2016:-:*:*:*:-:*:x86:*", "vulnerable": true, "matchCriteriaId": "BF3B9F15-3077-4BC5-9EC5-7416A9FBDC70"}, {"criteria": "cpe:2.3:a:microsoft:office_2019:-:*:*:*:*:*:x64:*", "vulnerable": true, "matchCriteriaId": "241CDE2B-ABD0-4EFF-8D73-1766E32FA20F"}, {"criteria": "cpe:2.3:a:microsoft:office_2019:-:*:*:*:*:*:x86:*", "vulnerable": true, "matchCriteriaId": "14D63E3F-A431-4DD8-979F-811E8DAC423D"}, {"criteria": "cpe:2.3:a:microsoft:office_2021:-:*:*:*:ltsc:-:x64:*", "vulnerable": true, "matchCriteriaId": "1D518075-3362-4D15-93B1-0E6C61518D16"}, {"criteria": "cpe:2.3:a:microsoft:office_2021:-:*:*:*:ltsc:-:x86:*", "vulnerable": true, "matchCriteriaId": "1059BEC6-C30B-4F0F-A878-5267A21CBD85"}, {"criteria": "cpe:2.3:a:microsoft:office_2021:-:*:*:*:ltsc:macos:-:*", "vulnerable": true, "matchCriteriaId": "0DB3EBBF-E0C4-4D5A-8D22-107463AD1DE4"}, {"criteria": "cpe:2.3:a:microsoft:office_2024:-:*:*:*:ltsc:-:x64:*", "vulnerable": true, "matchCriteriaId": "55A9AFDA-D77B-4CC7-ACE5-3A2ABDA257D8"}, {"criteria": "cpe:2.3:a:microsoft:office_2024:-:*:*:*:ltsc:-:x86:*", "vulnerable": true, "matchCriteriaId": "8887D177-26A3-4008-89B6-50A9E9830F13"}, {"criteria": "cpe:2.3:a:microsoft:office_2024:-:*:*:*:ltsc:macos:-:*", "vulnerable": true, "matchCriteriaId": "589B470B-9C2E-41E2-A44D-D8CCB4D2F933"}, {"criteria": "cpe:2.3:a:microsoft:sharepoint_server:*:*:*:*:subscription:*:*:*", "vulnerable": true, "matchCriteriaId": "5FA63EA8-B225-4E35-A6A3-DBDECF5AC4C8", "versionEndExcluding": "16.0.19725.20434"}, {"criteria": "cpe:2.3:a:microsoft:sharepoint_server:2016:*:*:*:enterprise:*:*:*", "vulnerable": true, "matchCriteriaId": "F815EF1D-7B60-47BE-9AC2-2548F99F10E4"}, {"criteria": "cpe:2.3:a:microsoft:sharepoint_server:2019:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "6122D014-5BF1-4AF4-8B4D-80205ED7785E"}], "operator": "OR"}]}], "sourceIdentifier": "secure@microsoft.com"}