CVE-2023-21706
HighCVSS 8.8Exploitation Probability (EPSS)
High risk90th percentile - higher than 90% of all known CVEs
Summary
Remote code execution vulnerability in Microsoft Exchange Server. An attacker could exploit it to run arbitrary code on the server.
Risk Assessment
Risk of full compromise of the mail server, potentially leading to data theft, espionage, or malware propagation.
Recommendation
Install the latest security updates for Microsoft Exchange Server.
Other vulnerabilities in Microsoft Exchange Server
See all- CVE-2026-87696High
Improper verification of cryptographic signature in Microsoft Exchange Server allows an authorized attacker to elevate privileges over a network.
- CVE-2026-87695High
A vulnerability in Microsoft Exchange Server involves inclusion of functionality from an untrusted control sphere. An authorized attacker can elevate privileges locally.
- CVE-2026-87692High
A deserialization of untrusted data vulnerability in Microsoft Exchange Server allows an authorized attacker to elevate privileges locally.
- CVE-2026-77910High
Incorrect authorization in Microsoft Exchange Server allows an authorized attacker to elevate privileges over a network.
- CVE-2026-70571High
Stack-based buffer overflow in Microsoft Exchange Server allows an unauthorized attacker to execute code over a network.
- CVE-2026-70279Critical
Improper neutralization of input during web page generation (cross-site scripting) in Microsoft Exchange Server allows an unauthorized attacker to perform spoofing over a network.
- CVE-2026-69641Critical
Missing authorization in Microsoft Exchange Server allows an authorized attacker to elevate privileges over a network.
- CVE-2026-69356Critical
Improper neutralization of input during web page generation ('cross-site scripting') in Microsoft Exchange Server allows an unauthorized attacker to perform spoofing over a network.
- CVE-2026-55008Critical
A cross-site scripting (XSS) vulnerability in Microsoft Exchange Server allows an unauthorized attacker to perform spoofing over a network. The flaw is due to improper neutralization of input during web page generation.
- CVE-2026-45502Medium
A Server-Side Request Forgery (SSRF) vulnerability in Microsoft Exchange Server allows an authorized attacker to disclose information over a network.
Original NVD description (English source)
Microsoft Exchange Server Remote Code Execution Vulnerability
Vulnerability data from NVD (NIST) · CISA KEV · EPSS