What is the CVSS score of EUVD-2025-20611?

EUVD-2025-20611 has a CVSS 3.1 base score of 9.8 (Critical). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. EPSS exploitation probability: 0.6%.

Is there a public PoC exploit available for EUVD-2025-20611?

Yes, a public proof-of-concept exploit is available for EUVD-2025-20611. Prioritise patching immediately. EPSS: 0.6%.

How to fix or mitigate EUVD-2025-20611?

Within 24 hours: Identify all Windows systems running SPNEGO (domain-joined systems, domain controllers, and servers using Kerberos authentication) and prioritize patching. Within 7 days: Apply Windows security updates containing the fix for CVE-2025-47981 to all identified systems, prioritizing domain controllers and externally-facing servers. Within 30 days: Complete patching of all remaining Windows systems in the organization and validate patch deployment through WSUS or endpoint management tools.

Windows EUVD-2025-20611

Q: Which versions of Windows are affected by EUVD-2025-20611?

CVE-2025-47981 is a critical remote code execution vulnerability in Windows SPNEGO Extended Negotiation (CVSS 9.8) that allows unauthenticated network attackers to execute arbitrary code on affected…. A patch is available.

| CVE-2025-47981 CRITICAL

Heap-based Buffer Overflow (CWE-122)

2025-07-08 secure@microsoft.com

Windows Buffer Overflow Heap Overflow Microsoft Windows 10 1507 Windows 10 1607 Windows 10 1809 Windows 10 21h2 Windows 10 22h2 Windows 11 22h2 Windows 11 23h2 Windows 11 24h2 Windows Server 2008 Windows Server 2012 Windows Server 2016 Windows Server 2019 Windows Server 2022 Windows Server 2022 23h2 Windows Server 2025

9.8

CVSS 3.1 · NVD

View

Vulnerability Assessment

Weakness	CWE CWE-122 OWASP Top 10:2025 A06:2021 - Vulnerable and Outdated Components ASVS 5.0 V15 - Secure Coding and Architecture Heap buffer bounds checking MITRE ATT&CK 1 technique across 1 tactic: Execution The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. Sign in to read
Impact	Successful exploitation can lead to arbitrary code execution, denial of service, or privilege escalation depending on the memory layout and protections in place. With a CVSS score of 9.8 (CRITICAL), this represents a critical risk.
Exploit ScenarioDerived	An attacker sends an oversized input to a vulnerable function, overwriting the return address on the stack to redirect execution to attacker-controlled shellcode.

Act Now Prioritize within 24-48h. Why: CRITICAL severity + public POC available.

Patch available 0.6% exploitation probability (EPSS)

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AnalysisAIv1 – Mar 16, 2026

Heap-based buffer overflow in Windows SPNEGO Extended Negotiation allows an unauthorized attacker to execute code over a network.

Earlier versions of this analysis (1)

v1 Mar 16, 2026 - 04:21 CVSS 9.8

RemediationAI

Use memory-safe languages or bounds-checked functions. Enable ASLR, DEP/NX, and stack canaries. Apply vendor patches promptly.

Affected VersionsENISA

Windows Server 2022 10.0.20348.0 <10.0.20348.3932

Windows 10 Version 22H2 10.0.19045.0 <10.0.19045.6093

Windows 10 Version 21H2 10.0.19044.0 <10.0.19044.6093

Windows 11 Version 24H2 10.0.26100.0 <10.0.26100.4652

Windows 10 Version 1507 10.0.10240.0 <10.0.10240.21073

Windows Server 2012 R2 (Server Core installation) 6.3.9600.0 <6.3.9600.22676

Windows Server 2019 10.0.17763.0 <10.0.17763.7558

Windows Server 2008 R2 Service Pack 1 (Server Core installation) 6.1.7601.0 <6.1.7601.27820

Windows 11 version 22H2 10.0.22621.0 <10.0.22621.5624

Windows Server 2022, 23H2 Edition (Server Core installation) 10.0.25398.0 <10.0.25398.1732

Windows 10 Version 1607 10.0.14393.0 <10.0.14393.8246

Windows Server 2025 10.0.26100.0 <10.0.26100.4652

Windows Server 2012 6.2.9200.0 <6.2.9200.25573

Windows Server 2019 (Server Core installation) 10.0.17763.0 <10.0.17763.7558

Windows 11 Version 23H2 10.0.22631.0 <10.0.22631.5624

Windows 11 version 22H3 10.0.22631.0 <10.0.22631.5624

Windows Server 2016 (Server Core installation) 10.0.14393.0 <10.0.14393.8246

Windows Server 2016 10.0.14393.0 <10.0.14393.8246

Windows Server 2008 R2 Service Pack 1 6.1.7601.0 <6.1.7601.27820

Windows Server 2025 (Server Core installation) 10.0.26100.0 <10.0.26100.4652

Windows 10 Version 1809 10.0.17763.0 <10.0.17763.7558

Windows Server 2012 R2 6.3.9600.0 <6.3.9600.22676

Windows Server 2012 (Server Core installation) 6.2.9200.0 <6.2.9200.25573

Affected Packages

euvd windows_10_version_1507 fix: 10.0.10240.21073

euvd windows_10_version_1607 fix: 10.0.14393.8246

euvd windows_10_version_1809 fix: 10.0.17763.7558

euvd windows_10_version_21h2 fix: 10.0.19044.6093

euvd windows_10_version_22h2 fix: 10.0.19045.6093

euvd windows_11_version_22h2 fix: 10.0.22621.5624

euvd windows_11_version_22h3 fix: 10.0.22631.5624

euvd windows_11_version_23h2 fix: 10.0.22631.5624

euvd windows_11_version_24h2 fix: 10.0.26100.4652

euvd windows_server_2008_r2_service_pack_1 fix: 6.1.7601.27820

euvd windows_server_2008_r2_service_pack_1_server_core_installation fix: 6.1.7601.27820

euvd windows_server_2012 fix: 6.2.9200.25573

euvd windows_server_2012_r2 fix: 6.3.9600.22676

euvd windows_server_2012_r2_server_core_installation fix: 6.3.9600.22676

euvd windows_server_2012_server_core_installation fix: 6.2.9200.25573

euvd windows_server_2016 fix: 10.0.14393.8246

euvd windows_server_2016_server_core_installation fix: 10.0.14393.8246

euvd windows_server_2019 fix: 10.0.17763.7558

euvd windows_server_2019_server_core_installation fix: 10.0.17763.7558

euvd windows_server_2022 fix: 10.0.20348.3932

euvd windows_server_2022_23h2_edition_server_core_installation fix: 10.0.25398.1732

euvd windows_server_2025 fix: 10.0.26100.4652

euvd windows_server_2025_server_core_installation fix: 10.0.26100.4652

Source: OSV (Open Source Vulnerabilities)

Affects your stack

Affects 23 packages in euvd

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

A buffer overflow occurs when data written to a buffer exceeds its allocated size, potentially overwriting adjacent memory and corrupting program state. This vulnerability is classified as Heap-based Buffer Overflow (CWE-122).

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Exploit and PoC references, threat intelligence from 22 sources

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Severity by source

NVD PRIMARY 9.8 CRITICAL

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

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Lifecycle Timeline

Analysis Updated

Apr 16, 2026 - 05:51 EUVD-patch-fix

executive summary

Patch available

Apr 16, 2026 - 05:29 EUVD

10.0.20348.3932,10.0.19045.6093,10.0.19044.6093

PoC Detected

Sep 26, 2025 - 17:24 vuln.today

Public exploit code

CVE Published

Jul 08, 2025 - 17:15 nvd

CRITICAL 9.8

Executive ViewAI

Why It Matters

CVE-2025-47981 is a critical remote code execution vulnerability in Windows SPNEGO Extended Negotiation (CVSS 9.8) that allows unauthenticated network attackers to execute arbitrary code on affected systems. This impacts all Windows systems using SPNEGO authentication and poses an immediate risk to domain-joined endpoints, servers, and authentication infrastructure without urgent patching.

Business Impact: Severe

Compensating Controls

Apply vendor patch. If immediate patching is not feasible, implement network segmentation to restrict SPNEGO authentication traffic to trusted internal networks only, disable SPNEGO where not required, and enforce additional monitoring on authentication protocols for suspicious activity patterns.

Threat Intelligence Overview

EPSS Score

0.6%

Top 31% exploitable

Exploit

POC

Public exploit code exists

Data Quality

4 sources

Confidence: Medium

EUVD

NVD

CVE.org

EPSS

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue

Severity CRITICAL

CISA KEV No

Public POC Yes

EPSS 0.6%

Patch available Yes

Active threat No

Deciding rule

CRITICAL severity + public POC available

What every action level means

Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.

Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.

This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.

This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.

Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision· derived

Out-of-Cycle

Exploitation· derived

Poc

System Exposure· derived

Open

Automatable· derived

Yes

Human Impact

Very High

Priority Score

Low Medium High Critical

KEV: 0

EPSS: +1

CVSS: +49

PoC: +20

Weaponized: 0

Threat intel: 0

Gov advisory: 0

Attack Technique

Buffer Overflow HIGH

A buffer overflow occurs when a program writes more data to a memory buffer than it was allocated to hold, causing the excess data to spill into adjacent memory regions.

Heap Overflow HIGH

A heap overflow occurs when a program writes data beyond the bounds of a buffer allocated in the heap memory region.