{"dataType": "CVE_RECORD", "containers": {"cna": {"metrics": [{"format": "CVSS", "cvssV2_0": {"version": "2.0", "baseScore": 7.5, "accessVector": "NETWORK", "vectorString": "AV:N/AC:L/Au:N/C:P/I:P/A:P", "authentication": "NONE", "integrityImpact": "PARTIAL", "accessComplexity": "LOW", "availabilityImpact": "PARTIAL", "confidentialityImpact": "PARTIAL"}}, {"format": "CVSS", "cvssV3_1": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 9.8, "attackVector": "NETWORK", "baseSeverity": "CRITICAL", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "NONE", "confidentialityImpact": "HIGH"}}, {"format": "CVSS", "cvssV3_1": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 9.1, "attackVector": "NETWORK", "baseSeverity": "CRITICAL", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N", "integrityImpact": "HIGH", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "NONE", "privilegesRequired": "NONE", "confidentialityImpact": "HIGH"}}], "affected": [{"cpes": ["cpe:2.3:a:microsoft:exchange_server:2013:cumulative_update_21:*:*:*:*:*:*", "cpe:2.3:a:microsoft:exchange_server:2013:cumulative_update_22:*:*:*:*:*:*", "cpe:2.3:a:microsoft:exchange_server:2013:cumulative_update_23:*:*:*:*:*:*", "cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_10:*:*:*:*:*:*", "cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_11:*:*:*:*:*:*", "cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_12:*:*:*:*:*:*", "cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_13:*:*:*:*:*:*", "cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_14:*:*:*:*:*:*", "cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_15:*:*:*:*:*:*", "cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_16:*:*:*:*:*:*", "cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_17:*:*:*:*:*:*", "cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_18:*:*:*:*:*:*", "cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_19:*:*:*:*:*:*", "cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_8:*:*:*:*:*:*", "cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_9:*:*:*:*:*:*", "cpe:2.3:a:microsoft:exchange_server:2019:-:*:*:*:*:*:*", "cpe:2.3:a:microsoft:exchange_server:2019:cumulative_update_1:*:*:*:*:*:*", "cpe:2.3:a:microsoft:exchange_server:2019:cumulative_update_2:*:*:*:*:*:*", "cpe:2.3:a:microsoft:exchange_server:2019:cumulative_update_3:*:*:*:*:*:*", "cpe:2.3:a:microsoft:exchange_server:2019:cumulative_update_4:*:*:*:*:*:*", "cpe:2.3:a:microsoft:exchange_server:2019:cumulative_update_5:*:*:*:*:*:*", "cpe:2.3:a:microsoft:exchange_server:2019:cumulative_update_6:*:*:*:*:*:*", "cpe:2.3:a:microsoft:exchange_server:2019:cumulative_update_7:*:*:*:*:*:*", "cpe:2.3:a:microsoft:exchange_server:2019:cumulative_update_8:*:*:*:*:*:*"], "vendor": "microsoft", "product": "exchange_server", "versions": [{"status": "affected", "version": "2013"}, {"status": "affected", "version": "2016"}, {"status": "affected", "version": "2019"}], "defaultStatus": "unaffected"}], "references": [{"url": "http://packetstormsecurity.com/files/161846/Microsoft-Exchange-2019-SSRF-Arbitrary-File-Write.html", "tags": ["exploit", "third-party-advisory", "vdb-entry"]}, {"url": "http://packetstormsecurity.com/files/161938/Microsoft-Exchange-ProxyLogon-Remote-Code-Execution.html", "tags": ["exploit", "third-party-advisory", "vdb-entry"]}, {"url": "http://packetstormsecurity.com/files/162610/Microsoft-Exchange-2019-Unauthenticated-Email-Download.html", "tags": ["exploit", "third-party-advisory", "vdb-entry"]}, {"url": "http://packetstormsecurity.com/files/162736/Microsoft-Exchange-ProxyLogon-Collector.html", "tags": ["exploit", "third-party-advisory", "vdb-entry"]}, {"url": "https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-26855", "tags": ["patch", "vendor-advisory"]}, {"url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-26855", "tags": ["x_us-government-resource"]}], "descriptions": [{"lang": "en", "value": "Microsoft Exchange Server Remote Code Execution Vulnerability"}, {"lang": "es", "value": "Una Vulnerabilidad de Ejecución de código remota de Microsoft Exchange Server. Este ID de CVE es diferente de CVE-2021-26412, CVE-2021-26854, CVE-2021-26857, CVE-2021-26858, CVE-2021-27065, CVE-2021-27078"}], "problemTypes": [{"descriptions": [{"lang": "en", "cweId": "CWE-918", "description": "CWE-918"}]}], "x_remediations": {"windows": [{"type": "update", "anyOf": ["KB5000871", "KB5001779", "KB5003435", "KB5003611", "KB5003612", "KB5004778", "KB5004779", "KB5004780", "KB5007011", "KB5007012", "KB5007409", "KB5008631", "KB5010324", "KB5012698", "KB5014260", "KB5014261", "KB5015321", "KB5015322", "KB5019076", "KB5019077", "KB5019758", "KB5022143", "KB5022188", "KB5022193", "KB5023038", "KB5024296", "KB5025903", "KB5026261", "KB5029388", "KB5030524", "KB5030877", "KB5032146", "KB5032147", "KB5036386", "KB5036401", "KB5036402", "KB5037224", "KB5044062", "KB5049233", "KB5057652", "KB5057653", "KB5063221", "KB5063222", "KB5063223", "KB5066367", "KB5066368", "KB5066369", "KB5066370", "KB5066371", "KB5066372"], "products": ["Microsoft Exchange Server 2013 Cumulative Update 21", "Microsoft Exchange Server 2013 Cumulative Update 22", "Microsoft Exchange Server 2013 Cumulative Update 23", "Microsoft Exchange Server 2016 Cumulative Update 10", "Microsoft Exchange Server 2016 Cumulative Update 11", "Microsoft Exchange Server 2016 Cumulative Update 12", "Microsoft Exchange Server 2016 Cumulative Update 13", "Microsoft Exchange Server 2016 Cumulative Update 14", "Microsoft Exchange Server 2016 Cumulative Update 15", "Microsoft Exchange Server 2016 Cumulative Update 16", "Microsoft Exchange Server 2016 Cumulative Update 17", "Microsoft Exchange Server 2016 Cumulative Update 18", "Microsoft Exchange Server 2016 Cumulative Update 19", "Microsoft Exchange Server 2016 Cumulative Update 8", "Microsoft Exchange Server 2016 Cumulative Update 9", "Microsoft Exchange Server 2019", "Microsoft Exchange Server 2019 Cumulative Update 1", "Microsoft Exchange Server 2019 Cumulative Update 2", "Microsoft Exchange Server 2019 Cumulative Update 3", "Microsoft Exchange Server 2019 Cumulative Update 4", "Microsoft Exchange Server 2019 Cumulative Update 5", "Microsoft Exchange Server 2019 Cumulative Update 6", "Microsoft Exchange Server 2019 Cumulative Update 7", "Microsoft Exchange Server 2019 Cumulative Update 8"]}]}, "providerMetadata": {"orgId": "00000000-0000-4000-A000-000000000003", "shortName": "nvd", "dateUpdated": "2021-03-03T00:15:12Z", "x_subShortName": "nvd"}}}, "cveMetadata": {"cveId": "CVE-2021-26855", "state": "PUBLISHED", "dateUpdated": "2025-10-30T19:55:58Z", "assignerOrgId": "f38d906d-7342-40ea-92c1-6c4a2c6478c8", "datePublished": "2021-03-03T00:15:12Z", "assignerShortName": "microsoft"}, "dataVersion": "5.0"}