CVE-2023-21529
Microsoft Exchange Server Remote Code Execution Vulnerability
CVE-2023-21529 is a high vulnerability (CVSS 8.8) in Microsoft Exchange Server, published February 14, 2023. CISA lists it as known to be exploited, since April 13, 2026. EUVD reports exploitation since April 13, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 59.3%, the 99th percentile. No source names a fixed version.
- Severity
- 8.8 HighCVSS 3.1, CVE List
- Exploit chance
- 59.3%EPSS, 99th percentile
- Exploitation
- ExploitedCISA KEV,
- Fixed in
- No fix listedNo source names one
Description
Microsoft Exchange Server Remote Code Execution Vulnerability
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
Affected products
What each source reports
CVE List Score used
Microsoft Exchange Server Remote Code Execution Vulnerability
Microsoft Exchange Server Remote Code Execution Vulnerability
- Record
CVE-2023-21529- CVSS 3.1
- 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 - Weakness
- CWE-502
- Updated
- 2026-11-02
EUVDEUVD-2023-25697
Microsoft Exchange Server Remote Code Execution Vulnerability
- Record
EUVD-2023-25697- CVSS 3.1
- 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 - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-hjxr-gv9h-rjxc
Microsoft Exchange Server Remote Code Execution Vulnerability
Microsoft Exchange Server Remote Code Execution Vulnerability
- Record
GHSA-hjxr-gv9h-rjxc- CVSS 3.1
- 8.8 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-502
- Updated
- 2026-11-02
CISA KEVNo score
Microsoft Exchange Server Deserialization of Untrusted Data Vulnerability
Microsoft Exchange Server contains a deserialization of untrusted data that allows an authenticated attacker to achieve remote code execution.
- Record
CVE-2023-21529- Weakness
- CWE-502
- Updated
- 2026-11-02
NVD
Microsoft Exchange Server Remote Code Execution Vulnerability
- Record
CVE-2023-21529- CVSS 3.1
- 8.8 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-502
- Updated
- 2026-11-02
History
| Recorded | Changed | Sources |
|---|---|---|
| exploitation | ||
| first indexed | CVE List, EUVD, GitHub Advisories, CISA KEV, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
References
msrc.microsoft.com/update-guide/vulnerability/CVE-2023-21529
microsoft.com/en-us/security/blog/2026/04/06/storm-1175-focuses-gaze-on-vulnerable-web-facing-assets-in-high-tempo-medusa-ransomware-operations
cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-21529
nvd.nist.gov/vuln/detail/CVE-2023-21529
github.com/advisories/GHSA-hjxr-gv9h-rjxc