Cyber Posture

CVE-2026-26106

High

Published: 10 March 2026

Published
10 March 2026
Modified
13 March 2026
KEV Added
Patch
CVSS Score 8.8 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0016 36.9th percentile
Risk Priority 18 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2026-26106 is a high-severity Improper Input Validation (CWE-20) vulnerability in Microsoft Sharepoint Server. Its CVSS base score is 8.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 36.9th 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-2 (Flaw Remediation).

Threat & Defense at a Glance

What attackers do: exploitation maps to Exploit Public-Facing Application (T1190). What defenders deploy: see the NIST 800-53 controls recommended below.
Threat & Defense Details

Mitigating Controls (NIST 800-53 r5)AI

prevent

Directly mandates information input validation mechanisms to prevent exploitation of the improper input validation flaw in Microsoft Office SharePoint.

prevent

Requires timely flaw remediation, such as applying patches for CVE-2026-26106, to eliminate the vulnerability enabling remote code execution.

detect

Vulnerability scanning identifies improper input validation issues like CVE-2026-26106 in SharePoint for proactive remediation.

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
Why these techniques?

The vulnerability is an improper input validation flaw in Microsoft Office SharePoint enabling remote arbitrary code execution for low-privileged authenticated users over the network, directly mapping to T1190: Exploit Public-Facing Application.

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

NVD Description

Improper input validation in Microsoft Office SharePoint allows an authorized attacker to execute code over a network.

Deeper analysisAI

CVE-2026-26106 is an improper input validation vulnerability (CWE-20) affecting Microsoft Office SharePoint. Published on 2026-03-10, it enables an authorized attacker to execute code over a network, earning a CVSS v3.1 base score of 8.8 (AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H).

An attacker with low privileges (PR:L), such as an authenticated user, can exploit this vulnerability remotely (AV:N) with low complexity and no user interaction required. Successful exploitation allows arbitrary code execution, resulting in high impacts to confidentiality, integrity, and availability.

The Microsoft Security Response Center advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-26106 provides details on patches and mitigation guidance.

Details

CWE(s)

Affected Products

microsoft
sharepoint server
2016, 2019 · ≤ 16.0.19725.20076

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References