SB2025080631 - Privilege escalation in Microsoft Exchange Server Hybrid Deployment
Published: August 6, 2025
Security Bulletin ID
SB2025080631
CSH Severity
Medium
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Remote access
Highest impact
Code execution
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 vulnerability.
1) Improper authentication (CVE-ID: CVE-2025-53786)
CWE-ID: CWE-287 - Improper Authentication
CVSSv4: CVSS:4.0/AV:N/AC:H/AT:N/PR:H/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/SA:H/E:U/U:Green
The vulnerability allows a remote attacker to escalate privileges in hybrid deployments.
The vulnerability exists due to improper authentication. A remote user with privileged access to an on-premises Exchange server can escalate privileges within the organization’s connected cloud environment without leaving easily detectable and auditable trace.
Remediation
Install update from vendor's website.