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TI-2023-08127 Aliases CVE-2023-21745GHSA-x5p9-xxf9-9475

Microsoft Exchange Server Spoofing Vulnerability

Priority MEDIUM 40CWE-502Published · Updated

Key facts

Attack vector
Adjacent network
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
Spoofing
Confidentiality · integrity · availability
High · High · High
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Microsoft. Impact type from Microsoft.

Summary

Microsoft Exchange Server Spoofing Vulnerability

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.01538 75th percentileScored 2026-11-07
Fix Fixed Microsoft: 2 updates

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
MicrosoftMicrosoft Exchange Server 2016 Cumulative Update 2315.01.0 to before 15.01.2507.01715.01.2507.017Patch availableCNA
MicrosoftMicrosoft Exchange Server 2019 Cumulative Update 1215.02.0 to before 15.02.1118.02115.02.1118.021Patch availableCNA
MicrosoftMicrosoft Exchange Server 2019 Cumulative Update 1115.02.0 to before 15.02.0986.03715.02.0986.037Patch availableCNA
  • Microsoft Exchange Server 2016 Cumulative Update 23 VendorMicrosoft Affected 15.01.0 to before 15.01.2507.017 Fixed in 15.01.2507.017 Patch available CNA
  • Microsoft Exchange Server 2019 Cumulative Update 12 VendorMicrosoft Affected 15.02.0 to before 15.02.1118.021 Fixed in 15.02.1118.021 Patch available CNA
  • Microsoft Exchange Server 2019 Cumulative Update 11 VendorMicrosoft Affected 15.02.0 to before 15.02.0986.037 Fixed in 15.02.0986.037 Patch available CNA

CPE configurations NVD · 3

CPEVersionsRoleVendor
cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_23:*:*:*:*:*:*2016 cumulative_update_23VulnerableMicrosoft
cpe:2.3:a:microsoft:exchange_server:2019:cumulative_update_11:*:*:*:*:*:*2019 cumulative_update_11VulnerableMicrosoft
cpe:2.3:a:microsoft:exchange_server:2019:cumulative_update_12:*:*:*:*:*:*2019 cumulative_update_12VulnerableMicrosoft
  • cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_23:*:*:*:*:*:* Versions 2016 cumulative_update_23 Vulnerable ·Microsoft
  • cpe:2.3:a:microsoft:exchange_server:2019:cumulative_update_11:*:*:*:*:*:* Versions 2019 cumulative_update_11 Vulnerable ·Microsoft
  • cpe:2.3:a:microsoft:exchange_server:2019:cumulative_update_12:*:*:*:*:*:* Versions 2019 cumulative_update_12 Vulnerable ·Microsoft

Remediation

Microsoft 2 updates

  • KB5022193
    Security Update
    • Microsoft Exchange Server 2019 Cumulative Update 11 15.02.0986.037
    • Microsoft Exchange Server 2019 Cumulative Update 12 15.02.1118.021
  • KB5022143
    Security Update
    • Microsoft Exchange Server 2016 Cumulative Update 23 15.01.2507.017

Vendor assessments

Microsoft

Microsoft's page for this CVE →

Impact
Spoofing
Exploited
No
Publicly disclosed
—
Exploitability
Exploitation More Likely

Timeline

  1. 2026-10-02 Threatist record created from CVE-2023-21745
  2. 2026-10-03 Alias added: GHSA-x5p9-xxf9-9475

References

Advisory 1

  • TI-2024-14170 Microsoft Exchange Server Elevation of Privilege Vulnerability KEVCVSS 3.1CRITICAL 9.8
  • TI-2022-19610 Microsoft Exchange Server Elevation of Privilege Vulnerability KEVCVSS 3.1CRITICAL 9.8
  • TI-2021-13547 Microsoft Exchange Server Elevation of Privilege Vulnerability KEVCVSS 3.1CRITICAL 9.8
  • TI-2021-13502 Microsoft Exchange Server Remote Code Execution Vulnerability KEVCVSS 3.1CRITICAL 9.8
  • TI-2021-08465 Microsoft Exchange Server Remote Code Execution Vulnerability KEVCVSS 3.1CRITICAL 9.8
  • TI-2023-07929 Microsoft Exchange Server Remote Code Execution Vulnerability KEVCVSS 3.1HIGH 8.8
See all 258 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences