CVE-2026-26131
Published: 10 March 2026
Summary
CVE-2026-26131 is a high-severity Incorrect Default Permissions (CWE-276) vulnerability in Microsoft .Net. Its CVSS base score is 7.8 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 6.1th 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 CM-6 (Configuration Settings) and SI-2 (Flaw Remediation).
Threat & Defense at a Glance
Threat & Defense Details
Mitigating Controls (NIST 800-53 r5)AI
Directly remediates the incorrect default permissions flaw in .NET through timely identification, testing, and deployment of vendor patches.
Ensures .NET components are configured with secure baseline settings, including correct file permissions, to block unauthorized privilege escalation.
Enforces least privilege for local accounts, limiting the scope and impact of privilege escalation exploits in .NET.
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
CVE describes local privilege escalation via exploitation of incorrect default permissions (CWE-276) in .NET, directly matching T1068 Exploitation for Privilege Escalation.
NVD Description
Incorrect default permissions in .NET allows an authorized attacker to elevate privileges locally.
Deeper analysisAI
CVE-2026-26131 involves incorrect default permissions in .NET, enabling an authorized attacker to elevate privileges locally. This vulnerability, associated with CWE-276, affects .NET components and carries a CVSS v3.1 base score of 7.8 (AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H). It was published on 2026-03-10.
A local attacker with low privileges can exploit this vulnerability with low attack complexity and no user interaction. Successful exploitation allows privilege escalation, resulting in high impacts to confidentiality, integrity, and availability.
Microsoft's update guide provides details on mitigation for CVE-2026-26131 at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-26131.
Details
- CWE(s)