TI-2026-73311 Aliases CVE-2026-102858 GHSA-r6w3-7r2g-5962

Heap-based buffer overflow in Microsoft Office OneNote enables code execution

MEDIUM 42CWE-122Published 2026-10-13 · Updated 2026-10-31

Key facts

Attack vector: Network
Privileges required: None
User interaction: Required
Attack complexity: Low
Impact type: Code execution
Confidentiality · integrity · availability: High · High · High
Fix status: Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-122 and the CVSS impact.

Summary

Microsoft Office 365 for Mac, Microsoft Office LTSC for Mac 2021 and Microsoft Office LTSC for Mac 2024 are affected in versions from 1.0.0 before 16.114.26101123, from 16.0.1 before 16.114.26101123 and from 16.0.0 before 16.114.26101123 respectively. A heap-based buffer overflow (CWE-122) in Microsoft Office OneNote lets an unauthorized attacker execute code over a network. Exploitation requires user interaction.

Written with Claude Haiku 5.5 from the sources below · 2026-10-28

Description from the CNA

Heap-based buffer overflow in Microsoft Office OneNote allows an unauthorized attacker to execute code over a network.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.00859 58th percentileScored 2026-11-07

Fix Fixed Microsoft Office 365 for Mac (Microsoft): 16.114.26101123Microsoft Office LTSC for Mac 2021 (Microsoft): 16.114.26101123+1 more product

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: None
Automatable: No
Technical impact: Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
Microsoft	Microsoft Office 365 for Mac	1.0.0 to before 16.114.26101123	16.114.26101123	Patch available	CNA
Microsoft	Microsoft Office LTSC for Mac 2021	16.0.1 to before 16.114.26101123	16.114.26101123	Patch available	CNA
Microsoft	Microsoft Office LTSC for Mac 2024	16.0.0 to before 16.114.26101123	16.114.26101123	Patch available	CNA

Microsoft Office 365 for Mac VendorMicrosoft Affected 1.0.0 to before 16.114.26101123 Fixed in 16.114.26101123 Patch available CNA
Microsoft Office LTSC for Mac 2021 VendorMicrosoft Affected 16.0.1 to before 16.114.26101123 Fixed in 16.114.26101123 Patch available CNA
Microsoft Office LTSC for Mac 2024 VendorMicrosoft Affected 16.0.0 to before 16.114.26101123 Fixed in 16.114.26101123 Patch available CNA

CPE configurations NVD · 3

CPE	Versions	Role	Vendor
cpe:2.3:a:microsoft:microsoft_365:-:::::macos::	not specified by NVD	Vulnerable	Microsoft
cpe:2.3:a:microsoft:office_2021:-::::ltsc:macos:-:	not specified by NVD	Vulnerable	Microsoft
cpe:2.3:a:microsoft:office_2024:-::::ltsc:macos:-:	not specified by NVD	Vulnerable	Microsoft

cpe:2.3:a:microsoft:microsoft_365:-:*:*:*:*:macos:*:* Versions not specified by NVD Vulnerable ·Microsoft
cpe:2.3:a:microsoft:office_2021:-:*:*:*:ltsc:macos:-:* Versions not specified by NVD Vulnerable ·Microsoft
cpe:2.3:a:microsoft:office_2024:-:*:*:*:ltsc:macos:-:* Versions not specified by NVD Vulnerable ·Microsoft

Remediation

Update Microsoft Office 365 for Mac, Microsoft Office LTSC for Mac 2021 and Microsoft Office LTSC for Mac 2024 to version 16.114.26101123 or later.

Written with Claude Haiku 5.5 from the sources below · 2026-10-28

Fix · CNA Microsoft Office 365 for Mac (Microsoft) Fixed in 16.114.26101123
Fix · CNA Microsoft Office LTSC for Mac 2021 (Microsoft) Fixed in 16.114.26101123
Fix · CNA Microsoft Office LTSC for Mac 2024 (Microsoft) Fixed in 16.114.26101123

Timeline

2026-10-13 Threatist record created from CVE-2026-102858
2026-10-13 Alias added: GHSA-r6w3-7r2g-5962
2026-10-14 CISA SSVC decision points changed
2026-10-14 Priority changed: MEDIUM → LOW
2026-10-14 Priority changed: LOW → MEDIUM
2026-10-16 Fix available: Microsoft/Microsoft Office 365 for [email protected], Microsoft/Microsoft Office LTSC for Mac [email protected], Microsoft/Microsoft Office LTSC for Mac [email protected] · CNA

References

Patch 1

Microsoft Office OneNote Remote Code Execution Vulnerability

TI-2026-72350 Heap overflow in Microsoft Office Outlook lets attackers run code CVSS 3.1CRITICAL 9.8
TI-2026-72959 Use after free in Microsoft PowerPoint allows remote code execution CVSS 3.1CRITICAL 9.8
TI-2026-72940 Stack overflow in Microsoft Office Outlook allows code execution CVSS 3.1CRITICAL 9.8
TI-2026-54593 Microsoft Office Outlook Remote Code Execution Vulnerability CVSS 3.1CRITICAL 9.8
TI-2026-54589 Microsoft Office Remote Code Execution Vulnerability CVSS 3.1HIGH 8.8
TI-2026-54594 Microsoft Outlook and Word Remote Code Execution Vulnerability CVSS 3.1HIGH 8.4

See all 367 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences