SB2026051542 - Spoofing attack via stored XSS in Microsoft Exchange Server OWA
Published: May 15, 2026
Security Bulletin ID
SB2026051542
CSH Severity
High
Patch available
NO
Number of vulnerabilities
1
Exploitation vector
Remote access
Highest impact
Data manipulation
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 vulnerability.
1) Stored cross-site scripting (CVE-ID: CVE-2026-42897)
The disclosed vulnerability allows a remote attacker to perform cross-site scripting (XSS) attacks.
The vulnerability exists due to insufficient sanitization of user-supplied data in Outlook Web Access. A remote attacker can send a specially crafted email message and execute arbitrary JavaScript code in the victim's browser once the email is viewed.
Note, the vulnerability is being actively exploited in the wild.
Remediation
Cybersecurity Help is not aware of any official remediation provided by the vendor.