CISA Adds One Known Exploited Vulnerability to Catalog
CISA adds CVE-2026-42897 Microsoft Exchange XSS vulnerability to KEV Catalog due to active exploitation.
Summary
CISA has added CVE-2026-42897, a cross-site scripting vulnerability in Microsoft Exchange Server, to its Known Exploited Vulnerabilities (KEV) Catalog based on evidence of active exploitation in the wild. The addition falls under Binding Operational Directive (BOD) 22-01, which mandates that Federal Civilian Executive Branch agencies remediate identified vulnerabilities by specified deadlines. CISA urges all organizations to prioritize patching this vulnerability as part of their vulnerability management practices.
Full text
Alert CISA Adds One Known Exploited Vulnerability to Catalog Release DateMay 15, 2026 CISA has added one new vulnerability to its Known Exploited Vulnerabilities (KEV) Catalog, based on evidence of active exploitation. CVE-2026-42897 Microsoft Exchange Server Cross-Site Scripting Vulnerability This type of vulnerability is a frequent attack vector for malicious cyber actors and poses significant risks to the federal enterprise. Binding Operational Directive (BOD) 22-01: Reducing the Significant Risk of Known Exploited Vulnerabilities established the KEV Catalog as a living list of known Common Vulnerabilities and Exposures (CVEs) that carry significant risk to the federal enterprise. BOD 22-01 requires Federal Civilian Executive Branch (FCEB) agencies to remediate identified vulnerabilities by the due date to protect FCEB networks against active threats. See the BOD 22-01 Fact Sheet for more information. Although BOD 22-01 only applies to FCEB agencies, CISA strongly urges all organizations to reduce their exposure to cyberattacks by prioritizing timely remediation of KEV Catalog vulnerabilities as part of their vulnerability management practice. CISA will continue to add vulnerabilities to the catalog that meet the specified criteria. This product is provided subject to this Notification and this Privacy & Use policy. Please share your thoughts We recently updated our anonymous product survey; we welcome your feedback.
Indicators of Compromise
- cve — CVE-2026-42897