CVEvulnerability

CVE-2026-42897

6.1 MEDIUM Known exploited Published 2026-05-14 Modified 2026-10-26 Official page ↗

CISA Known Exploited Vulnerability

Microsoft Exchange Server Cross-Site Scripting Vulnerability — Microsoft Microsoft

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.

Added to KEV: 2026-05-15
Remediation due: 2026-05-29
Ransomware use: Unknown
Required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Notes: https://msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2026-42897 ; https://learn.microsoft.com/en-us/exchange/plan-and-deploy/post-installation-tasks/security-best-practices/exchange-emergency-mitigation-service ; https://nvd.nist.gov/vuln/detail/CVE-2026-42897

Status: Analyzed
Published: 2026-05-14
Last modified: 2026-10-26
Assigner: [email protected]
CVSS 3.1 ([email protected]): 8.1 HIGH — CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N
CVSS 3.1 ([email protected]): 6.1 MEDIUM — CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Weaknesses: CWE-79

Description

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.

Affected configurations

• microsoft exchange server 2016 • microsoft exchange server 2019 • microsoft exchange server subscription edition (< 15.02.2562.043)

Weakness · CWE (1)

CWE-79 Improper Neutralization of Input During Web Page Generation weakness

References