Widely deployed Microsoft Exchange Server; XSS spoofing risk could enable phishing and credential theft.
CVE-2026-42897
XSS in Exchange Server allows spoofing via crafted web requests.
Is CVE-2026-42897 being exploited?
Yes. CVE-2026-42897 appears in CISA's Known Exploited Vulnerabilities catalog, which means exploitation in the wild has been confirmed and reported. Treat it as active rather than theoretical, and patch it ahead of higher-scoring vulnerabilities that carry no exploitation evidence.
How severe is CVE-2026-42897?
CVE-2026-42897 is rated High with a CVSS score of 8.1. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-42897?
Yes. A fix has been recorded for CVE-2026-42897. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-42897 affect?
CVE-2026-42897 affects Microsoft Exchange Server. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-42897?
Patch when released; enable mitigations and monitor.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Remote spoofing of user identity via XSS in Exchange web pages; possible phishing/credential theft.
Patch when possible
- affected>= 15.01.0.0 and < 15.01.2507.069
- affected>= 15.02.0.0 and < 15.02.1544.041
- affected>= 15.02.0.0 and < 15.02.1748.046
- affected>= 15.02.0.0 and < 15.02.2562.043
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.