CVE-2026-42897

HIGHNVD 8.19.0▲

8.1

Improper neutralization of input during web page generation ('cross-site scripting') in Microsoft Exchange Server allows an unauthorized attacker to perform spoofing over a network.

CVSS v3: 8.1
EG Score: 9.0(high)
EPSS: 91.0%
KEV: ⚠ Exploited

Published

May 14, 2026

Last Modified

May 15, 2026

Advisory Details (1)

Auto-updated May 14, 2026

Patch available. Sources: microsoft.

microsoft Patch Available

Security Update Guide - Microsoft Security Response Center

Security Update Guide - Microsoft Security Response Center. Patch available via Microsoft Security Update

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-42897

Vendor Advisories for CVE-2026-42897(2)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Frequently asked(6)

What is CVE-2026-42897?

CVE-2026-42897 is a high vulnerability published on May 14, 2026. Improper neutralization of input during web page generation ('cross-site scripting') in Microsoft Exchange Server allows an unauthorized attacker to perform spoofing over a network.

When was CVE-2026-42897 disclosed?

CVE-2026-42897 was first published in the National Vulnerability Database on May 14, 2026, with the most recent update on May 15, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.

Is CVE-2026-42897 actively exploited?

Yes. CISA added CVE-2026-42897 to the Known Exploited Vulnerabilities catalog on May 15, 2026, affecting Microsoft Microsoft. KEV listing indicates confirmed exploitation in the wild; this CVE warrants immediate patching attention.

What is the CVSS score of CVE-2026-42897?

CVE-2026-42897 has a CVSS v3 base score of 8.1 (NVD). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 9.0.

Which products are affected by CVE-2026-42897?

CVE-2026-42897 affects Microsoft Microsoft. The full affected-products list, including version ranges and fixed versions, is shown in the Affected Packages section of this page.

How do I remediate CVE-2026-42897?

Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-42897, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-42897

Explore →

Is Your Infrastructure Affected by CVE-2026-42897?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Start Free Scan →Browse All CVEs

CVE-2026-42897

📅 Published

🔄 Last Modified

📋 Advisory Details (1)

Security Update Guide - Microsoft Security Response Center

📣 Vendor Advisories for CVE-2026-42897(2)

❓ Frequently asked(6)