CVE-2021-26857

  1. OpenCVE
  2. Vulnerabilities (CVE)
  3. CVE-2021-26857
Microsoft Exchange Server Remote Code Execution Vulnerability

7.8 /10

CVSS v3 : HIGH

V3 Legend

Vector :

Exploitability : 1.8 / Impact : 5.9

Attack Vector LOCAL

Attack Complexity LOW

Privileges Required NONE

User Interaction REQUIRED

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

6.8 /10

CVSS v2.0 : MEDIUM

V2 Legend

Vector : AV:N/AC:M/Au:N/C:P/I:P/A:P

Exploitability : 8.6 / Impact : 6.4

Access Vector NETWORK

Access Complexity MEDIUM

Authentication NONE

Confidentiality Impact PARTIAL

Integrity Impact PARTIAL

Availability Impact PARTIAL

References
Link Resource
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-26857 Patch Vendor Advisory
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-26857 Patch Vendor Advisory
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-26857 US Government Resource
Configurations

Configuration 1 (hide)

OR cpe:2.3:a:microsoft:exchange_server:2010:sp3:*:*:*:*:*:*
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:2013:sp1:*:*:*:*:*:*
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:*:*:*:*:*:*
History

30 Oct 2025, 19:55

Type Values Removed Values Added
References () https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-26857 - () https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-26857 - US Government Resource

22 Oct 2025, 00:17

Type Values Removed Values Added
References
  • () https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-26857 -

21 Oct 2025, 20:18

Type Values Removed Values Added
References
  • {'url': 'https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-26857', 'source': '134c704f-9b21-4f2e-91b3-4a467353bcc0'}

21 Oct 2025, 19:18

Type Values Removed Values Added
References
  • () https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-26857 -

21 Nov 2024, 05:56

Type Values Removed Values Added
References () https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-26857 - Patch, Vendor Advisory () https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-26857 - Patch, Vendor Advisory

25 Jul 2024, 17:53

Type Values Removed Values Added
CPE cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_13:*:*:*:*:*:*
cpe:2.3:a:microsoft:exchange_server:2019:cumulative_update_3:*:*:*:*:*:*
cpe:2.3:a:microsoft:exchange_server:2013:cumulative_update_22:*:*:*:*:*:*
cpe:2.3:a:microsoft:exchange_server:2019:cumulative_update_4:*:*:*:*:*:*
cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_10:*:*:*:*:*:*
cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_16:*:*:*:*:*:*
cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_9:*:*:*:*:*:*
cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_8:*:*:*:*:*:*
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:2016:cumulative_update_11:*:*:*:*:*:*
cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_12:*:*:*:*:*:*
cpe:2.3:a:microsoft:exchange_server:2019:cumulative_update_6:*:*:*:*:*:*
cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_15:*:*:*:*:*:*
cpe:2.3:a:microsoft:exchange_server:2019:cumulative_update_5:*:*:*:*:*:*
cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_14:*:*:*:*:*:*
cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_17:*:*:*:*:*:*
cpe:2.3:a:microsoft:exchange_server:2013:sp1:*:*:*:*:*:*
cpe:2.3:a:microsoft:exchange_server:2019:-:*:*:*:*:*:*

29 Dec 2023, 17:16

Type Values Removed Values Added
Summary Microsoft Exchange Server Remote Code Execution Vulnerability This CVE ID is unique from CVE-2021-26412, CVE-2021-26854, CVE-2021-26855, CVE-2021-26858, CVE-2021-27065, CVE-2021-27078. Microsoft Exchange Server Remote Code Execution Vulnerability
Information

Published : 2021-03-03 00:15

Updated : 2025-10-30 19:55

NVD link : CVE-2021-26857

Mitre link : CVE-2021-26857

CVE.ORG link : CVE-2021-26857

JSON object : View

Products Affected

microsoft

  • exchange_server
CWE
CWE-502

Deserialization of Untrusted Data