Security Updates for Microsoft Exchange Server (October 2026)

critical Nessus Plugin ID 365663

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:

- 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-2026-70279)

- Stack-based buffer overflow in Microsoft Exchange Server allows an unauthorized attacker to execute code over a network. (CVE-2026-70571)

- Incorrect authorization in Microsoft Exchange Server allows an authorized attacker to elevate privileges over a network. (CVE-2026-77910)

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 the following security updates to address this issue:
-KB5128895
-KB5128896
-KB5128897
-KB5128898

See Also

https://support.microsoft.com/help/5128895

https://support.microsoft.com/help/5128896

https://support.microsoft.com/help/5128897

https://support.microsoft.com/help/5128898

Plugin Details

Severity: Critical

ID: 365663

File Name: smb_nt_ms26_oct_exchange_pt.nasl

Version: 1.2

Type: Local

Agent: windows

Published: 10/14/2026

Updated: 10/15/2026

Supported Sensors: Nessus Agent, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 4.9

Percentile: 58.38

CVSS v2

Risk Factor: High

Base Score: 9.4

Temporal Score: 7

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

CVSS Score Source: CVE-2026-70279

CVSS v3

Risk Factor: Critical

Base Score: 9.3

Temporal Score: 8.1

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

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

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

Exploit Ease: No known exploits are available

Patch Publication Date: 10/13/2026

Vulnerability Publication Date: 10/13/2026

Reference Information

CVE: CVE-2026-70279, CVE-2026-70571, CVE-2026-77910, CVE-2026-87692, CVE-2026-87695, CVE-2026-87696

CWE: 121, 347, 502, 79, 829, 863

MSFT: MS26-5128895, MS26-5128896, MS26-5128897, MS26-5128898

MSKB: 5128895, 5128896, 5128897, 5128898