Actively exploited in the wild
Microsoft Exchange Server Information Disclosure Vulnerability
Microsoft - Exchange Server · Listed in the CISA KEV since 2024-08-21. This indicates confirmed attacks in production environments.
Required action: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
CVE-2021-31196
HighCVSS 7.2KEVExploitation Probability (EPSS)
Very high risk99th percentile - higher than 99% of all known CVEs
Summary
A remote code execution vulnerability in Microsoft Exchange Server.
Risk Assessment
A remote attacker could exploit this to execute arbitrary code on the server, potentially leading to full server compromise and data breach.
Recommendation
Apply the latest security updates for Microsoft Exchange Server.
Other vulnerabilities in Microsoft Exchange Server
See all- 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.
- CVE-2026-42897HighActively exploited
Microsoft Exchange Server has an improper neutralization of input during web page generation, leading to a cross-site scripting vulnerability. This flaw allows an unauthorized attacker to perform spoofing over a network.
- CVE-2026-21527Medium
A flaw in the user interface of Microsoft Exchange Server leads to misrepresentation of critical information, allowing an unauthorized attacker to perform spoofing over a network.
- CVE-2025-53786High
On April 18th, 2025, Microsoft announced security changes for Exchange Server in hybrid deployments and accompanying hot fixes. Further investigation revealed specific security implications related to these changes.
- CVE-2024-21410CriticalActively exploited
Microsoft Exchange Server Elevation of Privilege Vulnerability. Technical details are not provided in the description.
- CVE-2023-38182High
A vulnerability in Microsoft Exchange Server allows for remote code execution. An attacker can exploit this flaw to gain control over the system.
- CVE-2023-38181High
A vulnerability in Microsoft Exchange Server allows attackers to spoof other email addresses. Exploiting this flaw could lead to email communication fraud.
Original NVD description (English source)
Microsoft Exchange Server Remote Code Execution Vulnerability