Security Updates for Microsoft Excel Products C2R (October 2026)

high Nessus Plugin ID 365621

Synopsis

The Microsoft Excel Products are affected by multiple vulnerabilities.

Description

The Microsoft Excel Products are missing security updates. It is, therefore, affected by multiple vulnerabilities:

- Heap-based buffer overflow in Microsoft Office Excel allows an unauthorized attacker to execute code over a network. (CVE-2026-97003, CVE-2026-97004, CVE-2026-97007, CVE-2026-97741, CVE-2026-97748, CVE-2026-97751, CVE-2026-97753, CVE-2026-97754, CVE-2026-97756, CVE-2026-97757, CVE-2026-97758, CVE-2026-97763, CVE-2026-97765, CVE-2026-97766, CVE-2026-97768, CVE-2026-97769, CVE-2026-97773, CVE-2026-97776, CVE-2026-97777, CVE-2026-97780, CVE-2026-100210)

- Stack-based buffer overflow in Microsoft Office Excel allows an unauthorized attacker to execute code over a network. (CVE-2026-97742, CVE-2026-97750, CVE-2026-97761, CVE-2026-97770)

- Use after free in Microsoft Office Excel allows an unauthorized attacker to execute code over a network.
(CVE-2026-97010, CVE-2026-97017, CVE-2026-97738, CVE-2026-97745, CVE-2026-97747, CVE-2026-97752, CVE-2026-97759, CVE-2026-97771, CVE-2026-97775, CVE-2026-100209, CVE-2026-100211, CVE-2026-100212)

- Double free in Microsoft Office Excel allows an unauthorized attacker to execute code over a network.
(CVE-2026-97767, CVE-2026-97772)

- Out-of-bounds read in Microsoft Office Excel allows an unauthorized attacker to execute code over a network. (CVE-2026-97755, CVE-2026-105718)

- Out-of-bounds write in Microsoft Office Excel allows an unauthorized attacker to execute code over a network. (CVE-2026-97762)

- Integer underflow (wrap or wraparound) in Microsoft Office Excel allows an unauthorized attacker to execute code over a network. (CVE-2026-97739, CVE-2026-97746)

- Integer overflow or wraparound in Microsoft Office Excel allows an unauthorized attacker to execute code over a network. (CVE-2026-97778)

- Buffer underwrite ('buffer underflow') in Microsoft Office Excel allows an unauthorized attacker to execute code over a network. (CVE-2026-97008)

- Use of uninitialized resource in Microsoft Office Excel allows an unauthorized attacker to execute code over a network. (CVE-2026-97011)

- Out-of-bounds read in Microsoft Office Excel allows an unauthorized attacker to disclose information over a network. (CVE-2026-97760, CVE-2026-97779)

- Use after free in Microsoft Office Excel allows an unauthorized attacker to disclose information over a network. (CVE-2026-97743)

- Exposure of sensitive system information to an unauthorized control sphere in Microsoft Office Excel allows an unauthorized attacker to disclose information over a network. (CVE-2026-97740)

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 patches to address these issues.

For Office 365, Office 2016 C2R, or Office 2019, ensure automatic updates are enabled or open any office app and manually perform an update.

Plugin Details

Severity: High

ID: 365621

File Name: smb_nt_ms26_oct_excel_c2r.nasl

Version: 1.2

Type: Local

Agent: windows

Family: Windows

Published: 10/14/2026

Updated: 10/15/2026

Supported Sensors: Nessus Agent, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 6.9

Percentile: 96.5

CVSS v2

Risk Factor: Critical

Base Score: 10

Temporal Score: 7.4

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

CVSS Score Source: CVE-2026-97780

CVSS v3

Risk Factor: High

Base Score: 8.8

Temporal Score: 7.7

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

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

Vulnerability Information

CPE: cpe:/a:microsoft:excel

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-2026-100209, CVE-2026-100210, CVE-2026-100211, CVE-2026-100212, CVE-2026-105718, CVE-2026-97003, CVE-2026-97004, CVE-2026-97007, CVE-2026-97008, CVE-2026-97010, CVE-2026-97011, CVE-2026-97017, CVE-2026-97738, CVE-2026-97739, CVE-2026-97740, CVE-2026-97741, CVE-2026-97742, CVE-2026-97743, CVE-2026-97745, CVE-2026-97746, CVE-2026-97747, CVE-2026-97748, CVE-2026-97750, CVE-2026-97751, CVE-2026-97752, CVE-2026-97753, CVE-2026-97754, CVE-2026-97755, CVE-2026-97756, CVE-2026-97757, CVE-2026-97758, CVE-2026-97759, CVE-2026-97760, CVE-2026-97761, CVE-2026-97762, CVE-2026-97763, CVE-2026-97765, CVE-2026-97766, CVE-2026-97767, CVE-2026-97768, CVE-2026-97769, CVE-2026-97770, CVE-2026-97771, CVE-2026-97772, CVE-2026-97773, CVE-2026-97775, CVE-2026-97776, CVE-2026-97777, CVE-2026-97778, CVE-2026-97779, CVE-2026-97780

Detections

Analytics