Microsoft Exchange Server Cross-Site Scripting Vulnerability
Microsoft Exchange Server contains a cross-site scripting vulnerability during web page generation in Outlook Web Access and when certain interaction conditions are met, arbitrary JavaScript can be executed in the browser context.
- Vendor
- Microsoft
- Product
- Microsoft
- CVSS
- 8.1
- EPSS (exploit probability)
- 70.7%
- Status
- kev
- CISA patch-by (BOD 22-01)
- Added to KEV
Is CVE-2026-42897 being exploited?
Yes. CISA added CVE-2026-42897 to its Known Exploited Vulnerabilities catalog on . CISA only lists a CVE when it has reliable evidence of exploitation in the wild. It is also listed in ENISA's EU Vulnerability Database (EUVD) exploited list.
FIRST's EPSS model puts the probability of exploitation activity in the next 30 days at 70.7% (scored October 25, 2026).
- CISA KEV[ LISTED ]
- ENISA EUVD (exploited)[ LISTED ]
- CIRCL KEV[ — ]
Catalog snapshot 2026-11-13. Full cross-catalog view: /kev-comparison
CVE-2026-42897 timeline
Every event links to its source. Catalog dates are each catalog's own; day offsets count from NVD publication. Data: JSON
What to do
CISA required actionApply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
US federal civilian agencies must remediate by (14 days after listing) under BOD 22-01. Everyone else: that deadline is a sensible upper bound, not a target. Vendor guidance and the NVD record are linked under Source above.
Other Microsoft CVEs we track
| CVE / Vulnerability | Severity | CVSS | EPSS | Added to KEV |
|---|---|---|---|---|
| CVE-2026-124194 Microsoft Office Outlook Missing User Interaction for Potentially Unsafe Action Vulnerability | [ MEDIUM ] | 6.5 | 1.6% | |
| CVE-2026-96951 Microsoft Windows Command Injection Vulnerability | [ HIGH ] | 8.8 | 9.8% | |
| CVE-2026-96940 Microsoft Exchange Server privilege escalation via weak authorizationwrite-up | [ HIGH ] | 8.8 | 2.7% | — |
| CVE-2026-65660 Microsoft SharePoint Code Injection Vulnerabilitywrite-up | [ HIGH ] | 8.8 | 9.9% | |
| CVE-2026-85889 Azure AI Foundry missing authentication allows unauthorized privilege escalationwrite-up | [ CRITICAL ] | 10.0 | 0.7% | — |
| CVE-2026-69843 Microsoft Fabric authentication bypass by spoofingwrite-up | [ CRITICAL ] | 10.0 | 0.9% | — |
| CVE-2026-85880 Microsoft Windows ALPC Heap Buffer Overflow Privilege Escalationwrite-up | [ HIGH ] | 7.8 | 0.4% | |
| CVE-2026-81963 Microsoft Windows Update Stack Link-Following Privilege Escalationwrite-up | [ HIGH ] | 7.8 | 7.1% |