CVE-2023-36756Exchange Server Insecure Deserialization
Microsoft Exchange Server Remote Code Execution Vulnerability
Published Sep 13, 2023 · Updated Oct 30, 2025
Key Facts
Patch in the next maintenance window- CVE-2023-36756 is a high-severity vulnerability (CVSS 8.0 v3.1) affecting Exchange Server (Microsoft), Microsoft Exchange Server 2016 Cumulative Update 23, Microsoft Exchange Server 2019 Cumulative Update 12 and 1 more product.
- It is not listed in any known-exploited vulnerabilities catalog. No public exploit code is known.
- EPSS estimates a 49% probability of exploitation in the next 30 days.
- Fixed versions are available, including Microsoft Exchange Server 2016 Cumulative Update 23 15.01.2507.032, Microsoft Exchange Server 2019 Cumulative Update 12 15.02.1118.037, Microsoft Exchange Server 2019 Cumulative Update 13 15.02.1258.025.
- Brandefense priority: patch in the next maintenance window, because of its high severity, although no exploitation is known.
Scores
CVSS v3.1
8.0
CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS (30-day exploit likelihood)
49%
Higher than 98.8% of all scored CVEs
Exploit maturity
None known
ATLAS score
43/100
Publication score, see How it works
Exploitation Verdict
KEV listed
Not listed
Federal due date
None
No federal due date
Ransomware use
Not reported
Attributed actors
None named
Exploit & Defence Guidance
Exploit maturity
None known
Public exploit code
0
Proof-of-concept links
In-the-wild evidence
0
Reports of active use
Advisories And Exploit References
- advisoryhttps://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2023-36756
- advisoryUSOM advisory
- advisoryhttps://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2023-36744
- advisoryhttps://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2023-36745
- advisoryhttps://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2023-36757
- advisoryhttps://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2023-36777
Description
Microsoft Exchange Server Remote Code Execution Vulnerability
Affected Products
6 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| Exchange ServerMicrosoft | 2016-cumulative_update_23, 2019-cumulative_update_12, 2019-cumulative_update_13 | n/a |
| Microsoft Exchange Server 2016 Cumulative Update 23 | >= 15.01.0 | 15.01.2507.032 |
| Microsoft Exchange Server 2019 Cumulative Update 12 | >= 15.02.0 | 15.02.1118.037 |
| Microsoft Exchange Server 2019 Cumulative Update 13 | >= 15.02.0 | 15.02.1258.025 |
Patched Releases
Microsoft Exchange Server 2016 Cumulative Update 23
15.01.2507.032
Microsoft Exchange Server 2019 Cumulative Update 12
15.02.1118.037
Microsoft Exchange Server 2019 Cumulative Update 13
15.02.1258.025
Timeline
Publicly disclosed
Sep 13, 2023
Last updated
Oct 30, 2025
Weakness Type
- CWE-502 Deserialization of Untrusted Data
References
- advisoryweb.nvd.nist.gov · vuln
- advisoryUSOM advisory
- advisoryweb.nvd.nist.gov · vuln
- advisoryweb.nvd.nist.gov · vuln
- advisoryweb.nvd.nist.gov · vuln
FAQ
Common Questions.
Microsoft Exchange Server Remote Code Execution Vulnerability
Affected: Exchange Server (Microsoft) versions 2016-cumulative_update_23, 2019-cumulative_update_12, 2019-cumulative_update_13; Microsoft Exchange Server 2016 Cumulative Update 23 versions >= 15.01.0; Microsoft Exchange Server 2019 Cumulative Update 12 versions >= 15.02.0, among others. The full list is in the CVE brief.
It is not listed in any known-exploited vulnerabilities catalog.
No, it is not currently listed in the CISA Known Exploited Vulnerabilities catalog.
No public exploit code is known.
Fixed versions are available, including Microsoft Exchange Server 2016 Cumulative Update 23 15.01.2507.032, Microsoft Exchange Server 2019 Cumulative Update 12 15.02.1118.037, Microsoft Exchange Server 2019 Cumulative Update 13 15.02.1258.025.
Brandefense priority: patch in the next maintenance window, because of its high severity, although no exploitation is known.
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