Microsoft Exchange Server Remote Code Execution Vulnerability
Summary
| CVE | CVE-2023-21529 |
|---|---|
| State | PUBLISHED |
| Assigner | microsoft |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2023-02-14 20:15:11 UTC |
| Updated | 2026-04-14 14:44:35 UTC |
| Description | Microsoft Exchange Server Remote Code Execution Vulnerability |
Risk And Classification
Primary CVSS: v3.1 8.8 HIGH from [email protected]
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS: 0.350170000 probability, percentile 0.970340000 (date 2026-04-16)
CISA KEV: Listed on 2026-04-13; due 2026-04-27; ransomware use Unknown
Problem Types: CWE-502 | CWE-502 CWE-502: Deserialization of Untrusted Data
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | [email protected] | Secondary | 8.8 | HIGH | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
| 3.1 | CNA | CVSS | 8.8 | HIGH | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C |
CVSS v3.1 Breakdown
Attack Vector
NetworkAttack Complexity
LowPrivileges Required
LowUser Interaction
NoneScope
UnchangedConfidentiality
HighIntegrity
HighAvailability
HighCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CISA Known Exploited Vulnerability
| Vendor | Microsoft |
|---|---|
| Product | Exchange Server |
| Name | Microsoft Exchange Server Deserialization of Untrusted Data Vulnerability |
| Required Action | Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable. |
| Notes | https://msrc.microsoft.com/update-guide/vulnerability/CVE-2023-21529 ; https://nvd.nist.gov/vuln/detail/CVE-2023-21529 |
NVD Known Affected Configurations (CPE 2.3)
| Type | Vendor | Product | Version | Update | Edition | Language |
|---|---|---|---|---|---|---|
| Application | Microsoft | Exchange Server | 2013 | cumulative_update_23 | All | All |
| Application | Microsoft | Exchange Server | 2016 | cumulative_update_23 | All | All |
| Application | Microsoft | Exchange Server | 2019 | cumulative_update_11 | All | All |
| Application | Microsoft | Exchange Server | 2019 | cumulative_update_12 | All | All |
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Microsoft | Microsoft Exchange Server 2019 Cumulative Update 12 | affected 15.02.0 15.02.1118.025 custom | x64-based Systems |
| CNA | Microsoft | Microsoft Exchange Server 2019 Cumulative Update 11 | affected 15.02.0 15.02.0986.041 custom | x64-based Systems |
| CNA | Microsoft | Microsoft Exchange Server 2013 Cumulative Update 23 | affected 15.00.0 15.00.1497.047 custom | x64-based Systems |
| CNA | Microsoft | Microsoft Exchange Server 2016 Cumulative Update 23 | affected 15.01.0 15.01.2507.021 custom | x64-based Systems |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| Security Update Guide - Microsoft Security Response Center | af854a3a-2127-422b-91ae-364da2661108 | msrc.microsoft.com | Patch, Vendor Advisory |
| www.cisa.gov/known-exploited-vulnerabilities-catalog | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | www.cisa.gov | US Government Resource |
| www.microsoft.com/en-us/security/blog/2026/04/06/storm-1175-focuses-gaze-on-vul... | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | www.microsoft.com | Technical Description |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
| CISA Known Exploited Vulnerabilities catalog | CISA | www.cisa.gov | kev |
No vendor comments have been submitted for this CVE.
Additional Advisory Data
| Source | Time | Event |
|---|---|---|
| ADP | 2026-04-13T00:00:00.000Z | CVE-2023-21529 added to CISA KEV |