Microsoft Exchange Server (September 2026)

high Nessus Plugin ID 343866

Synopsis

The Microsoft Exchange Server installed on the remote host is affected by multiple vulnerabilities.

Description

The Microsoft Exchange Server installed on the remote host is missing security updates. It is, therefore, affected by multiple vulnerabilities:

- Double free in Microsoft Exchange Server allows an unauthorized attacker to execute code over a network.
(CVE-2026-55007)

- External control of file name or path in Microsoft Exchange Server allows an authorized attacker to execute code over a network. (CVE-2026-69355)

- 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. (CVE-2026-69356)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

Solution

Microsoft has released a security update for Microsoft Exchange Server. Apply the applicable Security Update for your Exchange Server version.

See Also

https://support.microsoft.com/help/5121608

https://support.microsoft.com/help/5121609

https://support.microsoft.com/help/5121610

https://support.microsoft.com/help/5121611

Plugin Details

Severity: High

ID: 343866

File Name: smb_nt_ms26_sep_exchange.nasl

Version: 1.1

Type: Local

Agent: windows

Published: 9/8/2026

Updated: 9/8/2026

Supported Sensors: Nessus Agent, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 5

Percentile: 93.45

CVSS v2

Risk Factor: High

Base Score: 7.6

Vector: CVSS2#AV:N/AC:H/Au:N/C:C/I:C/A:C

CVSS Score Source: CVE-2026-55007

CVSS v3

Risk Factor: High

Base Score: 8.1

Vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

Vulnerability Information

CPE: cpe:/a:microsoft:exchange_server:2016, cpe:/a:microsoft:exchange_server:2019, cpe:/a:microsoft:exchange_server:subscription_edition

Required KB Items: SMB/MS_Bulletin_Checks/Possible

Patch Publication Date: 9/8/2026

Vulnerability Publication Date: 9/8/2026

Reference Information

CVE: CVE-2026-55007, CVE-2026-69355, CVE-2026-69356, CVE-2026-69361, CVE-2026-69375, CVE-2026-69378, CVE-2026-69380, CVE-2026-69382, CVE-2026-69641

CWE: 327, 415, 639, 674, 73, 79, 862, 918

MSFT: MS26-5121608, MS26-5121609, MS26-5121610, MS26-5121611

MSKB: 5121608, 5121609, 5121610, 5121611