High

Microsoft Exchange Server Remote Code Execution Vulnerability

Type: advisorySource: Official CVE ListKnown exploited1 source record

Announced 2 Mar 2021Group revision 1

CVE-2021-26858

Primary source · Revision 1

Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.

Security context

Source reference: cve:CVE-2021-26858

Microsoft Exchange Server 2013 Cumulative Update 21

Source reference: /containers/cna/affected/0/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

Microsoft Exchange Server 2013 Cumulative Update 22

Source reference: /containers/cna/affected/1/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

Microsoft Exchange Server 2013 Cumulative Update 23

Source reference: /containers/cna/affected/2/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

Microsoft Exchange Server 2016 Cumulative Update 10

Source reference: /containers/cna/affected/3/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

Microsoft Exchange Server 2016 Cumulative Update 11

Source reference: /containers/cna/affected/4/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

Microsoft Exchange Server 2016 Cumulative Update 12

Source reference: /containers/cna/affected/5/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

Microsoft Exchange Server 2016 Cumulative Update 13

Source reference: /containers/cna/affected/6/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

Microsoft Exchange Server 2016 Cumulative Update 14

Source reference: /containers/cna/affected/7/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

Microsoft Exchange Server 2016 Cumulative Update 15

Source reference: /containers/cna/affected/8/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

Microsoft Exchange Server 2016 Cumulative Update 16

Source reference: /containers/cna/affected/9/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

Microsoft Exchange Server 2016 Cumulative Update 17

Source reference: /containers/cna/affected/10/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

Microsoft Exchange Server 2016 Cumulative Update 18

Source reference: /containers/cna/affected/11/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

Microsoft Exchange Server 2016 Cumulative Update 19

Source reference: /containers/cna/affected/12/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

Microsoft Exchange Server 2016 Cumulative Update 8

Source reference: /containers/cna/affected/13/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

Microsoft Exchange Server 2016 Cumulative Update 9

Source reference: /containers/cna/affected/14/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

Microsoft Exchange Server 2019

Source reference: /containers/cna/affected/15/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

Microsoft Exchange Server 2019 Cumulative Update 1

Source reference: /containers/cna/affected/16/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

Microsoft Exchange Server 2019 Cumulative Update 2

Source reference: /containers/cna/affected/17/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

Microsoft Exchange Server 2019 Cumulative Update 3

Source reference: /containers/cna/affected/18/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

Microsoft Exchange Server 2019 Cumulative Update 4

Source reference: /containers/cna/affected/19/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

Microsoft Exchange Server 2019 Cumulative Update 5

Source reference: /containers/cna/affected/20/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

Microsoft Exchange Server 2019 Cumulative Update 6

Source reference: /containers/cna/affected/21/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

Microsoft Exchange Server 2019 Cumulative Update 7

Source reference: /containers/cna/affected/22/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

Microsoft Exchange Server 2019 Cumulative Update 8

Source reference: /containers/cna/affected/23/product

Affected versions: Not stated in this record
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

Structured affected-version data

Original package identities and version rules from this source.

[
  {
    "vendor": "Microsoft",
    "product": "Microsoft Exchange Server 2013 Cumulative Update 21",
    "versions": [
      {
        "status": "affected",
        "version": "15.00.0",
        "lessThan": "15.00.1395.012",
        "versionType": "custom"
      }
    ],
    "platforms": [
      "x64-based Systems"
    ]
  },
  {
    "vendor": "Microsoft",
    "product": "Microsoft Exchange Server 2013 Cumulative Update 22",
    "versions": [
      {
        "status": "affected",
        "version": "15.00.0",
        "lessThan": "15.00.1473.006",
        "versionType": "custom"
      }
    ],
    "platforms": [
      "x64-based Systems"
    ]
  },
  {
    "vendor": "Microsoft",
    "product": "Microsoft Exchange Server 2013 Cumulative Update 23",
    "versions": [
      {
        "status": "affected",
        "version": "15.00.0",
        "lessThan": "15.00.1497.012",
        "versionType": "custom"
      }
    ],
    "platforms": [
      "x64-based Systems"
    ]
  },
  {
    "vendor": "Microsoft",
    "product": "Microsoft Exchange Server 2016 Cumulative Update 10",
    "versions": [
      {
        "status": "affected",
        "version": "15.01.0",
        "lessThan": "15.01.1531.012",
        "versionType": "custom"
      }
    ],
    "platforms": [
      "x64-based Systems"
    ]
  },
  {
    "vendor": "Microsoft",
    "product": "Microsoft Exchange Server 2016 Cumulative Update 11",
    "versions": [
      {
        "status": "affected",
        "version": "15.01.0",
        "lessThan": "15.01.1591.018",
        "versionType": "custom"
      }
    ],
    "platforms": [
      "x64-based Systems"
    ]
  },
  {
    "vendor": "Microsoft",
    "product": "Microsoft Exchange Server 2016 Cumulative Update 12",
    "versions": [
      {
        "status": "affected",
        "version": "15.01.0",
        "lessThan": "15.01.1713.010",
        "versionType": "custom"
      }
    ],
    "platforms": [
      "x64-based Systems"
    ]
  },
  {
    "vendor": "Microsoft",
    "product": "Microsoft Exchange Server 2016 Cumulative Update 13",
    "versions": [
      {
        "status": "affected",
        "version": "15.01.0",
        "lessThan": "15.01.1779.008",
        "versionType": "custom"
      }
    ],
    "platforms": [
      "x64-based Systems"
    ]
  },
  {
    "vendor": "Microsoft",
    "product": "Microsoft Exchange Server 2016 Cumulative Update 14",
    "versions": [
      {
        "status": "affected",
        "version": "15.01.0",
        "lessThan": "15.01.1847.012",
        "versionType": "custom"
      }
    ],
    "platforms": [
      "x64-based Systems"
    ]
  },
  {
    "vendor": "Microsoft",
    "product": "Microsoft Exchange Server 2016 Cumulative Update 15",
    "versions": [
      {
        "status": "affected",
        "version": "15.01.0",
        "lessThan": "15.01.1913.012",
        "versionType": "custom"
      }
    ],
    "platforms": [
      "x64-based Systems"
    ]
  },
  {
    "vendor": "Microsoft",
    "product": "Microsoft Exchange Server 2016 Cumulative Update 16",
    "versions": [
      {
        "status": "affected",
        "version": "15.01.0",
        "lessThan": "15.01.1979.008",
        "versionType": "custom"
      }
    ],
    "platforms": [
      "x64-based Systems"
    ]
  },
  {
    "vendor": "Microsoft",
    "product": "Microsoft Exchange Server 2016 Cumulative Update 17",
    "versions": [
      {
        "status": "affected",
        "version": "15.01.0",
        "lessThan": "15.01.2044.013",
        "versionType": "custom"
      }
    ],
    "platforms": [
      "x64-based Systems"
    ]
  },
  {
    "vendor": "Microsoft",
    "product": "Microsoft Exchange Server 2016 Cumulative Update 18",
    "versions": [
      {
        "status": "affected",
        "version": "15.01.0",
        "lessThan": "15.01.2106.013",
        "versionType": "custom"
      }
    ],
    "platforms": [
      "x64-based Systems"
    ]
  },
  {
    "vendor": "Microsoft",
    "product": "Microsoft Exchange Server 2016 Cumulative Update 19",
    "versions": [
      {
        "status": "affected",
        "version": "15.01.0",
        "lessThan": "15.01.2176.009",
        "versionType": "custom"
      }
    ],
    "platforms": [
      "x64-based Systems"
    ]
  },
  {
    "vendor": "Microsoft",
    "product": "Microsoft Exchange Server 2016 Cumulative Update 8",
    "versions": [
      {
        "status": "affected",
        "version": "15.01.0",
        "lessThan": "15.01.1415.010",
        "versionType": "custom"
      }
    ],
    "platforms": [
      "x64-based Systems"
    ]
  },
  {
    "vendor": "Microsoft",
    "product": "Microsoft Exchange Server 2016 Cumulative Update 9",
    "versions": [
      {
        "status": "affected",
        "version": "15.01.0",
        "lessThan": "15.01.1466.016",
        "versionType": "custom"
      }
    ],
    "platforms": [
      "x64-based Systems"
    ]
  },
  {
    "vendor": "Microsoft",
    "product": "Microsoft Exchange Server 2019",
    "versions": [
      {
        "status": "affected",
        "version": "15.02.0",
        "lessThan": "15.02.0221.018",
        "versionType": "custom"
      }
    ],
    "platforms": [
      "x64-based Systems"
    ]
  },
  {
    "vendor": "Microsoft",
    "product": "Microsoft Exchange Server 2019 Cumulative Update 1",
    "versions": [
      {
        "status": "affected",
        "version": "15.02.0",
        "lessThan": "15.01.1979.006",
        "versionType": "custom"
      }
    ],
    "platforms": [
      "x64-based Systems"
    ]
  },
  {
    "vendor": "Microsoft",
    "product": "Microsoft Exchange Server 2019 Cumulative Update 2",
    "versions": [
      {
        "status": "affected",
        "version": "15.02.0",
        "lessThan": "15.02.0397.011",
        "versionType": "custom"
      }
    ],
    "platforms": [
      "x64-based Systems"
    ]
  },
  {
    "vendor": "Microsoft",
    "product": "Microsoft Exchange Server 2019 Cumulative Update 3",
    "versions": [
      {
        "status": "affected",
        "version": "15.02.0",
        "lessThan": "15.02.0464.015",
        "versionType": "custom"
      }
    ],
    "platforms": [
      "x64-based Systems"
    ]
  },
  {
    "vendor": "Microsoft",
    "product": "Microsoft Exchange Server 2019 Cumulative Update 4",
    "versions": [
      {
        "status": "affected",
        "version": "15.02.0",
        "lessThan": "15.02.0659.012",
        "versionType": "custom"
      }
    ],
    "platforms": [
      "x64-based Systems"
    ]
  },
  {
    "vendor": "Microsoft",
    "product": "Microsoft Exchange Server 2019 Cumulative Update 5",
    "versions": [
      {
        "status": "affected",
        "version": "15.02.0",
        "lessThan": "15.02.0595.008",
        "versionType": "custom"
      }
    ],
    "platforms": [
      "x64-based Systems"
    ]
  },
  {
    "vendor": "Microsoft",
    "product": "Microsoft Exchange Server 2019 Cumulative Update 6",
    "versions": [
      {
        "status": "affected",
        "version": "15.02.0",
        "lessThan": "15.02.0529.013",
        "versionType": "custom"
      }
    ],
    "platforms": [
      "x64-based Systems"
    ]
  },
  {
    "vendor": "Microsoft",
    "product": "Microsoft Exchange Server 2019 Cumulative Update 7",
    "versions": [
      {
        "status": "affected",
        "version": "15.02.0",
        "lessThan": "15.02.0721.013",
        "versionType": "custom"
      }
    ],
    "platforms": [
      "x64-based Systems"
    ]
  },
  {
    "vendor": "Microsoft",
    "product": "Microsoft Exchange Server 2019 Cumulative Update 8",
    "versions": [
      {
        "status": "affected",
        "version": "15.02.0",
        "lessThan": "15.02.0792.010",
        "versionType": "custom"
      }
    ],
    "platforms": [
      "x64-based Systems"
    ]
  }
]

Related CVEs: CVE-2021-26858
Source reference: /cveMetadata/cveId

Publisher severity

high

Source reference: /containers/cna/metrics

Linked CVE context

These ratings describe the referenced vulnerabilities and products. They are not a severity rating for every application using this dependency.

CVE-2021-26858 · Unrated

Exchange Server · Known exploited (CISA KEV)

Event: #7747 · Revision 1
Added to Heist Feed: Sat, 24 Oct 2026 22:49:42 GMT
Publisher date: Tue, 02 Mar 2021 23:55:27 GMT

Read the original announcement

Revision history

24 Oct 2026CVE-2021-26858 · Revision 1Source updated