Cyber Posture

CVE-2026-26127

High

Published: 10 March 2026

Published
10 March 2026
Modified
01 April 2026
KEV Added
Patch
CVSS Score 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS Score 0.0009 26.2th percentile
Risk Priority 15 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2026-26127 is a high-severity Out-of-bounds Read (CWE-125) vulnerability in Microsoft .Net. Its CVSS base score is 7.5 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Application or System Exploitation (T1499.004); ranked at the 26.2th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

Threat & Defense at a Glance

What attackers do: exploitation maps to Application or System Exploitation (T1499.004).
Threat & Defense Details

MITRE ATT&CK Enterprise TechniquesAI

T1499.004 Application or System Exploitation Impact
Adversaries may exploit software vulnerabilities that can cause an application or system to crash and deny availability to users.
Why these techniques?

Out-of-bounds read in .NET enables remote unauthenticated crash of processes (C:N/I:N/A:H), directly matching application/system exploitation for endpoint DoS.

Confidence: HIGH · MITRE ATT&CK Enterprise v18.1

NVD Description

Out-of-bounds read in .NET allows an unauthorized attacker to deny service over a network.

Deeper analysisAI

CVE-2026-26127 is an out-of-bounds read vulnerability (CWE-125) affecting the .NET framework. Published on March 10, 2026, it enables an unauthorized attacker to cause a denial of service over a network. The vulnerability carries a CVSS v3.1 base score of 7.5 (AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H), indicating high severity primarily due to its impact on availability.

An unauthenticated attacker can exploit this flaw remotely with low complexity and no user interaction required. By triggering the out-of-bounds read, the attacker can crash .NET processes, leading to denial of service on affected systems hosting .NET applications.

Microsoft's Security Response Center provides mitigation guidance in its update advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-26127, recommending the application of available patches to .NET installations.

Details

CWE(s)

Affected Products

microsoft
.net
10.0.0 — 10.0.4 · 9.0.0 — 9.0.14
microsoft
bcl.memory
9.0.0 — 9.0.14 · 10.0.0 — 10.0.4

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References