Cyber Posture

CVE-2026-26110

High

Published: 10 March 2026

Published
10 March 2026
Modified
13 March 2026
KEV Added
Patch
CVSS Score 8.4 CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0006 18.7th percentile
Risk Priority 17 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2026-26110 is a high-severity Type Confusion (CWE-843) vulnerability in Microsoft Office Long Term Servicing Channel. Its CVSS base score is 8.4 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Client Execution (T1203); ranked at the 18.7th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified are NIST 800-53 SI-10 (Information Input Validation) and SI-16 (Memory Protection).

Threat & Defense at a Glance

What attackers do: exploitation maps to Exploitation for Client Execution (T1203). What defenders deploy: see the NIST 800-53 controls recommended below.
Threat & Defense Details

Mitigating Controls (NIST 800-53 r5)AI

prevent

Directly mitigates CVE-2026-26110 by requiring timely installation of Microsoft patches to remediate the type confusion vulnerability in Office.

prevent

Provides memory safety mechanisms like ASLR and DEP to block arbitrary code execution from type confusion exploits in Microsoft Office.

prevent

Enforces validation of Office document inputs to prevent type confusion by ensuring compatibility with expected data types and structures.

MITRE ATT&CK Enterprise TechniquesAI

T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
Why these techniques?

Type confusion vulnerability in Microsoft Office enables arbitrary code execution via client-side exploitation (T1203).

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

NVD Description

Access of resource using incompatible type ('type confusion') in Microsoft Office allows an unauthorized attacker to execute code locally.

Deeper analysisAI

CVE-2026-26110 is a type confusion vulnerability (CWE-843), involving access of a resource using an incompatible type, affecting Microsoft Office. Published on 2026-03-10T18:18:39.480, it carries a CVSS v3.1 base score of 8.4 (AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H), indicating high severity due to its potential for significant impact.

The vulnerability can be exploited by an unauthorized local attacker with low complexity and no required privileges or user interaction. Successful exploitation allows the attacker to execute arbitrary code locally on the affected system, resulting in high impacts to confidentiality, integrity, and availability.

Mitigation details are available in the Microsoft Security Response Center advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-26110.

Details

CWE(s)

Affected Products

microsoft
365 apps
all versions
microsoft
office
2016, 2019 · ≤ 16.0.19822.20000
microsoft
office long term servicing channel
2021, 2024

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References