Status: KEV | Advisory ID: CVE-2023-21529
| CVE | CVE-2023-21529 |
| Affected products | Microsoft Exchange Server |
| Exploitation status | Listed in CISA's Known Exploited Vulnerabilities (KEV) catalog, indicating confirmed active exploitation. |
| Classified as | CWE-502 (Deserialization of Untrusted Data) |
| KEV listing | Added to CISA's Known Exploited Vulnerabilities (KEV) catalog on 2026-04-13. |
| Exploitation prediction (EPSS) | 62% probability of exploitation in the next 30 days (99% percentile) -- FIRST.org's EPSS model. |
| Federal remediation deadline | 2026-04-27 (CISA KEV, Binding Operational Directive). |
Microsoft Exchange Server contains a deserialization of untrusted data that allows an authenticated attacker to achieve remote code execution.
| Source | Reference |
|---|---|
| NVD | https://nvd.nist.gov/vuln/detail/CVE-2023-21529 |