What is the CVSS score of EUVD-2026-56406?

EUVD-2026-56406 has a CVSS 3.1 base score of 7.0 (High). CVSS vector: CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H. EPSS exploitation probability: 0.3%.

Which versions of .NET Framework are affected by EUVD-2026-56406?

A critical security flaw in Microsoft .NET Framework and .NET runtimes exposes organizations to application-level compromise-any attacker with local access can execute malicious code within…. A patch is available.

Is there a public PoC exploit available for EUVD-2026-56406?

Yes, a public proof-of-concept exploit is available for EUVD-2026-56406. Prioritise patching immediately. EPSS: 0.3%.

How to fix or mitigate EUVD-2026-56406?

Within 24 hours, conduct a comprehensive inventory of all systems running affected .NET Framework versions (3.5-4.8.1) and .NET runtimes (8.0, 9.0, 10.0) as well as Visual Studio 2022 and 2026 installations to determine organizational scope and system criticality. Within 7 days, prioritize patch deployment beginning with production systems; apply Microsoft's vendor-released patches across all affected product lines to eliminate the integer overflow vulnerability. Within 30 days, complete full validation of patched environments through testing of applications dependent on these .NET runtimes and document remediation completion across all systems.

.NET Framework EUVD-2026-56406

| CVE-2026-62897 HIGH

Integer Overflow or Wraparound (CWE-190)

2026-08-11 secure@microsoft.com

GHSA-fx4q-gjrx-2jw6

Integer Overflow Buffer Overflow Net Framework Visual Studio 2022 Visual Studio 2026 Net

7.0

CVSS 3.1 · Vendor: microsoft

Severity by source

Vendor (microsoft) PRIMARY

7.0 HIGH

AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H

ENISA EUVD

HIGH

qualitative

vuln.today AI

7.0 HIGH

Local-only attack with high complexity and mandatory user interaction; no privileges required; full C/I/A process impact with no scope change to other systems.

3.1 AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H

4.0 AV:L/AC:H/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

Primary rating from Vendor (microsoft).

CVSS VectorVendor: microsoft

CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H

Attack Vector

Local

Attack Complexity

High

Privileges Required

None

User Interaction

Required

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Lifecycle Timeline

Analysis Generated

Aug 11, 2026 - 19:00 vuln.today

Patch available

Aug 11, 2026 - 18:19 EUVD

CVE Published

Aug 11, 2026 - 17:18 nvd

HIGH 7.0

DescriptionCVE.org

Integer overflow or wraparound in .NET Framework allows an unauthorized attacker to execute code locally.

AnalysisAI

Integer overflow in Microsoft .NET Framework and modern .NET runtimes enables local code execution with full process compromise (C:H/I:H/A:H) across a broad product surface spanning .NET Framework 3.5 through 4.8.1, .NET 8.0, 9.0, 10.0, and Visual Studio 2022 and 2026. An attacker who can deliver crafted input processed by a vulnerable .NET application can trigger arithmetic wraparound (CWE-190) to corrupt runtime memory and execute arbitrary code within the process context. …

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Attack ChainAIDerived

Hypothetical attack flow derived from CVE metadata

Access

Deliver crafted payload to local user

Delivery

User opens or executes vulnerable .NET application processing payload

Exploit

Integer overflow produces undersized heap allocation

Execution

Heap corruption overwrites adjacent runtime memory

Impact

Attacker-controlled code executes as application process user

Access

Deliver crafted payload to local user

Delivery

User opens or executes vulnerable .NET application processing payload

Exploit

Integer overflow produces undersized heap allocation

Execution

Heap corruption overwrites adjacent runtime memory

Impact

Attacker-controlled code executes as application process user

Vulnerability AssessmentAI

Exploitation	The target system must be running one of the nine affected product configurations-specifically .NET Framework 3.5 through 4.8.1, .NET 8.0, 9.0, or 10.0, or Visual Studio 2022 17.14 or 2026 18.8-without the corresponding security update applied. … Additional conditions and limiting factors are described in the full assessment.
Risk Assessment	The CVSS 3.1 vector CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H scores 7.0 (High), but several constraints meaningfully reduce real-world urgency relative to that score. … Full risk analysis with EPSS, KEV, and SSVC signal comparison available after sign-in.
Exploit Scenario	An attacker crafts a malicious file or data stream-such as a specially constructed binary, document, or network-delivered payload-designed to be processed by a .NET application running an unpatched runtime. When a victim user opens or executes the crafted content locally, an integer overflow in .NET's internal memory allocation logic triggers an undersized buffer, and subsequent writes corrupt adjacent heap or stack memory, redirecting execution flow to attacker-controlled shellcode running with the privileges of the .NET application process. …
Remediation	Apply Microsoft-released patches for each affected product line via Windows Update, the .NET release channel, or the Visual Studio updater. … Detailed patch versions, workarounds, and compensating controls in full report.

Recommended ActionAI

Within 24 hours, conduct a comprehensive inventory of all systems running affected .NET Framework versions (3.5-4.8.1) and .NET runtimes (8.0, 9.0, 10.0) as well as Visual Studio 2022 and 2026 installations to determine organizational scope and system criticality. …

Threat intelligence, references, and detailed analysis are available after sign-in.