CVE-2023-21529

HIGHNVD 8.89.0▲Trending — 5 sources updated this weekExploited in the wild

8.8

Microsoft Exchange Server Remote Code Execution Vulnerability

CVSS v3: 8.8
EG Score: 9.0(high)
EPSS: 96.5%
KEV: ⚠ Exploited

Published

February 14, 2023

Last Modified

April 14, 2026

Advisory Details (3)

Auto-updated May 19, 2026

⚠️ Active exploitation confirmed. Patch available. Sources: microsoft, cisa.

generic

Storm-1175 focuses gaze on vulnerable web-facing assets in high-tempo Medusa ransomware operations | Microsoft Security Blog

https://www.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 Patch Available🔴 Active Exploitation

Known Exploited Vulnerabilities Catalog | CISA

Known Exploited Vulnerabilities Catalog | CISA. Listed in CISA Known Exploited Vulnerabilities catalog.

https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-21529

microsoft Patch Available

Security Update Guide - Microsoft Security Response Center

Security Update Guide - Microsoft Security Response Center. Patch available via Microsoft Security Update

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2023-21529

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

CWE-502Deserialization of Untrusted Data

All Vendor Advisories

(1)

Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.

Microsoft MSRCCVE-2023-215292023-02-14
Microsoft Exchange Server Remote Code Execution Vulnerability

Data Freshness Timeline

(refreshed 20× in last 7d / 20× in last 30d)

Every time one of our enrichment pipelines (NVD, MITRE cvelistV5, EPSS, CISA KEV, GHSA, OSV, vendor advisories) ran against this CVE. Most recent first.

2026-06-04 18:52 UTCEG score recompute
2026-06-04 18:52 UTCVendor advisory
2026-06-04 18:52 UTCGHSA enrichment
2026-06-04 15:14 UTCEG score recompute
2026-06-04 15:14 UTCVendor advisory
2026-06-04 15:14 UTCGHSA enrichment
2026-06-04 11:36 UTCEG score recompute
2026-06-04 11:36 UTCVendor advisory
2026-06-04 11:36 UTCGHSA enrichment
2026-06-04 07:58 UTCEG score recompute
2026-06-04 07:58 UTCVendor advisory
2026-06-04 07:58 UTCGHSA enrichment
2026-06-04 04:20 UTCEG score recompute
2026-06-04 04:20 UTCVendor advisory
2026-06-04 04:20 UTCGHSA enrichment
2026-06-04 00:42 UTCEG score recompute
2026-06-04 00:42 UTCVendor advisory
2026-06-04 00:42 UTCGHSA enrichment
2026-06-03 21:04 UTCEG score recompute
2026-06-03 21:04 UTCVendor advisory

Frequently asked(6)

What is CVE-2023-21529?

CVE-2023-21529 is a high vulnerability published on February 14, 2023. Microsoft Exchange Server Remote Code Execution Vulnerability

When was CVE-2023-21529 disclosed?

CVE-2023-21529 was first published in the National Vulnerability Database on February 14, 2023, with the most recent update on April 14, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.

Is CVE-2023-21529 actively exploited?

Yes. CISA added CVE-2023-21529 to the Known Exploited Vulnerabilities catalog on April 13, 2026, affecting Microsoft Exchange Server. KEV listing indicates confirmed exploitation in the wild; this CVE warrants immediate patching attention.

What is the CVSS score of CVE-2023-21529?

CVE-2023-21529 has a CVSS v3 base score of 8.8 (NVD). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 9.0.

Which products are affected by CVE-2023-21529?

CVE-2023-21529 affects Microsoft Exchange Server. The full affected-products list, including version ranges and fixed versions, is shown in the Affected Packages section of this page.

How do I remediate CVE-2023-21529?

Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2023-21529, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2023-21529

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Is Your Infrastructure Affected by CVE-2023-21529?

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CVE-2023-21529

Published

Last Modified

Advisory Details (3)

Storm-1175 focuses gaze on vulnerable web-facing assets in high-tempo Medusa ransomware operations | Microsoft Security Blog

Known Exploited Vulnerabilities Catalog | CISA

Security Update Guide - Microsoft Security Response Center

Weakness Classification(1)

All Vendor Advisories

Data Freshness Timeline

Frequently asked(6)

Dependency Blast Radius

Is Your Infrastructure Affected by CVE-2023-21529?

Same vendor

Same CWE

CVE-2023-21529

📅 Published

🔄 Last Modified

📋 Advisory Details (3)

Storm-1175 focuses gaze on vulnerable web-facing assets in high-tempo Medusa ransomware operations | Microsoft Security Blog

Known Exploited Vulnerabilities Catalog | CISA

Security Update Guide - Microsoft Security Response Center

Weakness Classification(1)

All Vendor Advisories

Data Freshness Timeline

❓ Frequently asked(6)

Dependency Blast Radius

Is Your Infrastructure Affected by CVE-2023-21529?

🔗 Related CVEs(same vendor + same CWE)

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Published

Last Modified

Advisory Details (3)

Frequently asked(6)

Related CVEs(same vendor + same CWE)