On April 18th 2025, Microsoft announced Exchange Server Security Changes for Hybrid Deployments and accompanying non-security Hot Fix. Microsoft made these changes in the general interest of improving the security of hybrid Exchange deployments. Following further investigation, Microsoft identified specific security implications tied to the guidance and configuration steps outlined in the April announcement. Microsoft is issuing CVE-2025-53786 to document a vulnerability that is addressed by taking the steps documented with the April 18th announcement. Microsoft strongly recommends reading the information, installing the April 2025 (or later) Hot Fix and implementing the changes in your Exchange Server and hybrid environment.
Published: 2025-08-07
Frequently asked questions about CVE-2025-53786, an elevation of privilege vulnerability affecting Microsoft Exchange Server Hybrid Deployments.
https://www.theregister.com/2025/08/07/microsoft_cisa_warn_yet_another/
https://www.infosecurity-magazine.com/news/microsoft-exchange-vulnerability/
https://www.hipaajournal.com/warning-high-severity-flaw-microsoft-exchange-hybrid-deployments/
https://www.helpnetsecurity.com/2025/08/07/exchange-hybrid-deployment-vulnerability-cve-2025-53786/
https://www.databreachtoday.com/microsoft-warns-hybrid-exchange-deployment-flaw-a-29147
https://therecord.media/microsoft-exchange-server-vulnerability-cisa-alert
https://thehackernews.com/2025/08/microsoft-discloses-exchange-server.html
https://cyberscoop.com/cisa-microsoft-exchange-vulnerability/
Published: 2025-08-06
Updated: 2025-08-06
Base Score: 6.8
Vector: CVSS2#AV:N/AC:H/Au:M/C:C/I:C/A:C
Severity: Medium
Base Score: 8
Vector: CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H
Severity: High
EPSS: 0.00082
Tenable Research has classified this CVE under the following Vulnerability Watch classification, which includes active and historical (inactive) classifications. You can learn more about these classifications on our blog.
Vulnerability Being Monitored