MSRC_CVE-2026-26154
Vulnerability from csaf_microsoft - Published: 2026-04-14 07:00 - Updated: 2026-04-14 07:00Summary
Windows Server Update Service (WSUS) Tampering Vulnerability
Severity
Important
Notes
Additional Resources: To determine the support lifecycle for your software, see the Microsoft Support Lifecycle: https://support.microsoft.com/lifecycle
Disclaimer: The information provided in the Microsoft Knowledge Base is provided \"as is\" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply.
Customer Action: Required. The vulnerability documented by this CVE requires customer action to resolve.
CWE-20
- Improper Input Validation
Affected products
Fixed
13 products
| Product | Identifier | Version | Remediation |
|---|---|---|---|
|
Windows Server 2012 6.2.9200.26026
Windows Server 2012
|
6.2.9200.26026 | ||
|
Windows Server 2012 (Server Core installation) 6.2.9200.26026
Windows Server 2012 (Server Core installation)
|
6.2.9200.26026 | ||
|
Windows Server 2012 R2 6.3.9600.23132
Windows Server 2012 R2
|
6.3.9600.23132 | ||
|
Windows Server 2012 R2 (Server Core installation) 6.3.9600.23132
Windows Server 2012 R2 (Server Core installation)
|
6.3.9600.23132 | ||
|
Windows Server 2016 10.0.14393.9060
Windows Server 2016
|
10.0.14393.9060 | ||
|
Windows Server 2016 (Server Core installation) 10.0.14393.9060
Windows Server 2016 (Server Core installation)
|
10.0.14393.9060 | ||
|
Windows Server 2019 10.0.17763.8644
Windows Server 2019
|
10.0.17763.8644 | ||
|
Windows Server 2019 (Server Core installation) 10.0.17763.8644
Windows Server 2019 (Server Core installation)
|
10.0.17763.8644 | ||
|
Windows Server 2022 10.0.20348.5020
Windows Server 2022
|
10.0.20348.5020 | ||
|
Windows Server 2022 (Server Core installation) 10.0.20348.5020
Windows Server 2022 (Server Core installation)
|
10.0.20348.5020 | ||
|
Windows Server 2022, 23H2 Edition (Server Core installation) 10.0.25398.2274
Windows Server 2022, 23H2 Edition (Server Core installation)
|
10.0.25398.2274 | ||
|
Windows Server 2025 10.0.26100.32690
Windows Server 2025
|
10.0.26100.32690 | ||
|
Windows Server 2025 (Server Core installation) 10.0.26100.32690
Windows Server 2025 (Server Core installation)
|
10.0.26100.32690 |
Known affected
13 products
| Product | Identifier | Version | Remediation |
|---|---|---|---|
|
Windows Server 2025 (Server Core installation) <10.0.26100.32690
Windows Server 2025 (Server Core installation)
|
<10.0.26100.32690 |
Vendor Fix
fix
|
|
|
Windows Server 2025 <10.0.26100.32690
Windows Server 2025
|
<10.0.26100.32690 |
Vendor Fix
fix
|
|
|
Windows Server 2022, 23H2 Edition (Server Core installation) <10.0.25398.2274
Windows Server 2022, 23H2 Edition (Server Core installation)
|
<10.0.25398.2274 |
Vendor Fix
fix
|
|
|
Windows Server 2022 (Server Core installation) <10.0.20348.5020
Windows Server 2022 (Server Core installation)
|
<10.0.20348.5020 |
Vendor Fix
fix
|
|
|
Windows Server 2022 <10.0.20348.5020
Windows Server 2022
|
<10.0.20348.5020 |
Vendor Fix
fix
|
|
|
Windows Server 2019 (Server Core installation) <10.0.17763.8644
Windows Server 2019 (Server Core installation)
|
<10.0.17763.8644 |
Vendor Fix
fix
|
|
|
Windows Server 2019 <10.0.17763.8644
Windows Server 2019
|
<10.0.17763.8644 |
Vendor Fix
fix
|
|
|
Windows Server 2016 (Server Core installation) <10.0.14393.9060
Windows Server 2016 (Server Core installation)
|
<10.0.14393.9060 |
Vendor Fix
fix
|
|
|
Windows Server 2016 <10.0.14393.9060
Windows Server 2016
|
<10.0.14393.9060 |
Vendor Fix
fix
|
|
|
Windows Server 2012 R2 (Server Core installation) <6.3.9600.23132
Windows Server 2012 R2 (Server Core installation)
|
<6.3.9600.23132 |
Vendor Fix
fix
|
|
|
Windows Server 2012 R2 <6.3.9600.23132
Windows Server 2012 R2
|
<6.3.9600.23132 |
Vendor Fix
fix
|
|
|
Windows Server 2012 (Server Core installation) <6.2.9200.26026
Windows Server 2012 (Server Core installation)
|
<6.2.9200.26026 |
Vendor Fix
fix
|
|
|
Windows Server 2012 <6.2.9200.26026
Windows Server 2012
|
<6.2.9200.26026 |
Vendor Fix
fix
|
Threats
Impact
Tampering
Exploit Status
Publicly Disclosed:No;Exploited:No;Latest Software Release:Exploitation Less Likely
References
7 references
Acknowledgments
f7d8c52bec79e42795cf15888b85cbad
{
"document": {
"acknowledgments": [
{
"names": [
"f7d8c52bec79e42795cf15888b85cbad"
]
}
],
"aggregate_severity": {
"namespace": "https://www.microsoft.com/en-us/msrc/security-update-severity-rating-system",
"text": "Important"
},
"category": "csaf_security_advisory",
"csaf_version": "2.0",
"distribution": {
"text": "Public",
"tlp": {
"label": "WHITE",
"url": "https://www.first.org/tlp/"
}
},
"lang": "en-US",
"notes": [
{
"category": "general",
"text": "To determine the support lifecycle for your software, see the Microsoft Support Lifecycle: https://support.microsoft.com/lifecycle",
"title": "Additional Resources"
},
{
"category": "legal_disclaimer",
"text": "The information provided in the Microsoft Knowledge Base is provided \\\"as is\\\" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply.",
"title": "Disclaimer"
},
{
"category": "general",
"text": "Required. The vulnerability documented by this CVE requires customer action to resolve.",
"title": "Customer Action"
}
],
"publisher": {
"category": "vendor",
"contact_details": "secure@microsoft.com",
"name": "Microsoft Security Response Center",
"namespace": "https://msrc.microsoft.com"
},
"references": [
{
"category": "self",
"summary": "CVE-2026-26154 Windows Server Update Service (WSUS) Tampering Vulnerability - HTML",
"url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-26154"
},
{
"category": "self",
"summary": "CVE-2026-26154 Windows Server Update Service (WSUS) Tampering Vulnerability - CSAF",
"url": "https://msrc.microsoft.com/csaf/advisories/2026/msrc_cve-2026-26154.json"
},
{
"category": "external",
"summary": "Microsoft Exploitability Index",
"url": "https://www.microsoft.com/en-us/msrc/exploitability-index?rtc=1"
},
{
"category": "external",
"summary": "Microsoft Support Lifecycle",
"url": "https://support.microsoft.com/lifecycle"
},
{
"category": "external",
"summary": "Common Vulnerability Scoring System",
"url": "https://www.first.org/cvss"
}
],
"title": "Windows Server Update Service (WSUS) Tampering Vulnerability",
"tracking": {
"current_release_date": "2026-04-14T07:00:00.000Z",
"generator": {
"date": "2026-04-14T16:56:51.683Z",
"engine": {
"name": "MSRC Generator",
"version": "1.0"
}
},
"id": "msrc_CVE-2026-26154",
"initial_release_date": "2026-04-14T07:00:00.000Z",
"revision_history": [
{
"date": "2026-04-14T07:00:00.000Z",
"legacy_version": "1",
"number": "1",
"summary": "Information published."
}
],
"status": "final",
"version": "1"
}
},
"product_tree": {
"branches": [
{
"branches": [
{
"category": "product_version_range",
"name": "\u003c10.0.17763.8644",
"product": {
"name": "Windows Server 2019 \u003c10.0.17763.8644",
"product_id": "7"
}
},
{
"category": "product_version",
"name": "10.0.17763.8644",
"product": {
"name": "Windows Server 2019 10.0.17763.8644",
"product_id": "11571"
}
}
],
"category": "product_name",
"name": "Windows Server 2019"
},
{
"branches": [
{
"category": "product_version_range",
"name": "\u003c10.0.17763.8644",
"product": {
"name": "Windows Server 2019 (Server Core installation) \u003c10.0.17763.8644",
"product_id": "6"
}
},
{
"category": "product_version",
"name": "10.0.17763.8644",
"product": {
"name": "Windows Server 2019 (Server Core installation) 10.0.17763.8644",
"product_id": "11572"
}
}
],
"category": "product_name",
"name": "Windows Server 2019 (Server Core installation)"
},
{
"branches": [
{
"category": "product_version_range",
"name": "\u003c10.0.20348.5020",
"product": {
"name": "Windows Server 2022 \u003c10.0.20348.5020",
"product_id": "5"
}
},
{
"category": "product_version",
"name": "10.0.20348.5020",
"product": {
"name": "Windows Server 2022 10.0.20348.5020",
"product_id": "11923"
}
}
],
"category": "product_name",
"name": "Windows Server 2022"
},
{
"branches": [
{
"category": "product_version_range",
"name": "\u003c10.0.20348.5020",
"product": {
"name": "Windows Server 2022 (Server Core installation) \u003c10.0.20348.5020",
"product_id": "4"
}
},
{
"category": "product_version",
"name": "10.0.20348.5020",
"product": {
"name": "Windows Server 2022 (Server Core installation) 10.0.20348.5020",
"product_id": "11924"
}
}
],
"category": "product_name",
"name": "Windows Server 2022 (Server Core installation)"
},
{
"branches": [
{
"category": "product_version_range",
"name": "\u003c10.0.26100.32690",
"product": {
"name": "Windows Server 2025 (Server Core installation) \u003c10.0.26100.32690",
"product_id": "1"
}
},
{
"category": "product_version",
"name": "10.0.26100.32690",
"product": {
"name": "Windows Server 2025 (Server Core installation) 10.0.26100.32690",
"product_id": "12437"
}
}
],
"category": "product_name",
"name": "Windows Server 2025 (Server Core installation)"
},
{
"branches": [
{
"category": "product_version_range",
"name": "\u003c10.0.25398.2274",
"product": {
"name": "Windows Server 2022, 23H2 Edition (Server Core installation) \u003c10.0.25398.2274",
"product_id": "3"
}
},
{
"category": "product_version",
"name": "10.0.25398.2274",
"product": {
"name": "Windows Server 2022, 23H2 Edition (Server Core installation) 10.0.25398.2274",
"product_id": "12244"
}
}
],
"category": "product_name",
"name": "Windows Server 2022, 23H2 Edition (Server Core installation)"
},
{
"branches": [
{
"category": "product_version_range",
"name": "\u003c10.0.26100.32690",
"product": {
"name": "Windows Server 2025 \u003c10.0.26100.32690",
"product_id": "2"
}
},
{
"category": "product_version",
"name": "10.0.26100.32690",
"product": {
"name": "Windows Server 2025 10.0.26100.32690",
"product_id": "12436"
}
}
],
"category": "product_name",
"name": "Windows Server 2025"
},
{
"branches": [
{
"category": "product_version_range",
"name": "\u003c10.0.14393.9060",
"product": {
"name": "Windows Server 2016 \u003c10.0.14393.9060",
"product_id": "9"
}
},
{
"category": "product_version",
"name": "10.0.14393.9060",
"product": {
"name": "Windows Server 2016 10.0.14393.9060",
"product_id": "10816"
}
}
],
"category": "product_name",
"name": "Windows Server 2016"
},
{
"branches": [
{
"category": "product_version_range",
"name": "\u003c10.0.14393.9060",
"product": {
"name": "Windows Server 2016 (Server Core installation) \u003c10.0.14393.9060",
"product_id": "8"
}
},
{
"category": "product_version",
"name": "10.0.14393.9060",
"product": {
"name": "Windows Server 2016 (Server Core installation) 10.0.14393.9060",
"product_id": "10855"
}
}
],
"category": "product_name",
"name": "Windows Server 2016 (Server Core installation)"
},
{
"branches": [
{
"category": "product_version_range",
"name": "\u003c6.2.9200.26026",
"product": {
"name": "Windows Server 2012 \u003c6.2.9200.26026",
"product_id": "13"
}
},
{
"category": "product_version",
"name": "6.2.9200.26026",
"product": {
"name": "Windows Server 2012 6.2.9200.26026",
"product_id": "10378"
}
}
],
"category": "product_name",
"name": "Windows Server 2012"
},
{
"branches": [
{
"category": "product_version_range",
"name": "\u003c6.2.9200.26026",
"product": {
"name": "Windows Server 2012 (Server Core installation) \u003c6.2.9200.26026",
"product_id": "12"
}
},
{
"category": "product_version",
"name": "6.2.9200.26026",
"product": {
"name": "Windows Server 2012 (Server Core installation) 6.2.9200.26026",
"product_id": "10379"
}
}
],
"category": "product_name",
"name": "Windows Server 2012 (Server Core installation)"
},
{
"branches": [
{
"category": "product_version_range",
"name": "\u003c6.3.9600.23132",
"product": {
"name": "Windows Server 2012 R2 \u003c6.3.9600.23132",
"product_id": "11"
}
},
{
"category": "product_version",
"name": "6.3.9600.23132",
"product": {
"name": "Windows Server 2012 R2 6.3.9600.23132",
"product_id": "10483"
}
}
],
"category": "product_name",
"name": "Windows Server 2012 R2"
},
{
"branches": [
{
"category": "product_version_range",
"name": "\u003c6.3.9600.23132",
"product": {
"name": "Windows Server 2012 R2 (Server Core installation) \u003c6.3.9600.23132",
"product_id": "10"
}
},
{
"category": "product_version",
"name": "6.3.9600.23132",
"product": {
"name": "Windows Server 2012 R2 (Server Core installation) 6.3.9600.23132",
"product_id": "10543"
}
}
],
"category": "product_name",
"name": "Windows Server 2012 R2 (Server Core installation)"
}
]
},
"vulnerabilities": [
{
"cve": "CVE-2026-26154",
"cwe": {
"id": "CWE-20",
"name": "Improper Input Validation"
},
"notes": [
{
"category": "general",
"text": "Microsoft",
"title": "Assigning CNA"
},
{
"category": "faq",
"text": "An attacker can send specially crafted packets which could affect availability of the service and result in Denial of Service (DoS).",
"title": "According to the CVSS metrics, successful exploitation of this vulnerability could lead to major loss of availability (A:H). What does that mean for this vulnerability?"
}
],
"product_status": {
"fixed": [
"10378",
"10379",
"10483",
"10543",
"10816",
"10855",
"11571",
"11572",
"11923",
"11924",
"12244",
"12436",
"12437"
],
"known_affected": [
"1",
"2",
"3",
"4",
"5",
"6",
"7",
"8",
"9",
"10",
"11",
"12",
"13"
]
},
"references": [
{
"category": "self",
"summary": "CVE-2026-26154 Windows Server Update Service (WSUS) Tampering Vulnerability - HTML",
"url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-26154"
},
{
"category": "self",
"summary": "CVE-2026-26154 Windows Server Update Service (WSUS) Tampering Vulnerability - CSAF",
"url": "https://msrc.microsoft.com/csaf/advisories/2026/msrc_cve-2026-26154.json"
}
],
"remediations": [
{
"category": "vendor_fix",
"date": "2026-04-14T07:00:00.000Z",
"details": "10.0.17763.8644:Security Update:https://support.microsoft.com/help/5082123",
"product_ids": [
"7",
"6"
],
"url": "https://support.microsoft.com/help/5082123"
},
{
"category": "vendor_fix",
"date": "2026-04-14T07:00:00.000Z",
"details": "10.0.20348.5020:Security Update:https://support.microsoft.com/help/5082142",
"product_ids": [
"5",
"4"
],
"url": "https://support.microsoft.com/help/5082142"
},
{
"category": "vendor_fix",
"date": "2026-04-14T07:00:00.000Z",
"details": "10.0.26100.32690:Security Update:https://support.microsoft.com/help/5082063",
"product_ids": [
"1",
"2"
],
"url": "https://support.microsoft.com/help/5082063"
},
{
"category": "vendor_fix",
"date": "2026-04-14T07:00:00.000Z",
"details": "10.0.25398.2274:Security Update:https://support.microsoft.com/help/5082060",
"product_ids": [
"3"
],
"url": "https://support.microsoft.com/help/5082060"
},
{
"category": "vendor_fix",
"date": "2026-04-14T07:00:00.000Z",
"details": "10.0.14393.9060:Security Update:https://support.microsoft.com/help/5082198",
"product_ids": [
"9",
"8"
],
"url": "https://support.microsoft.com/help/5082198"
},
{
"category": "vendor_fix",
"date": "2026-04-14T07:00:00.000Z",
"details": "6.2.9200.26026:Monthly Rollup:https://support.microsoft.com/help/5082127",
"product_ids": [
"13",
"12"
],
"url": "https://support.microsoft.com/help/5082127"
},
{
"category": "vendor_fix",
"date": "2026-04-14T07:00:00.000Z",
"details": "6.3.9600.23132:Monthly Rollup:https://support.microsoft.com/help/5082126",
"product_ids": [
"11",
"10"
],
"url": "https://support.microsoft.com/help/5082126"
}
],
"scores": [
{
"cvss_v3": {
"attackComplexity": "LOW",
"attackVector": "NETWORK",
"availabilityImpact": "HIGH",
"baseScore": 7.5,
"baseSeverity": "HIGH",
"confidentialityImpact": "NONE",
"environmentalsScore": 0.0,
"exploitCodeMaturity": "UNPROVEN",
"integrityImpact": "NONE",
"privilegesRequired": "NONE",
"remediationLevel": "OFFICIAL_FIX",
"reportConfidence": "CONFIRMED",
"scope": "UNCHANGED",
"temporalScore": 6.5,
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C",
"version": "3.1"
},
"products": [
"1",
"2",
"3",
"4",
"5",
"6",
"7",
"8",
"9",
"10",
"11",
"12",
"13"
]
}
],
"threats": [
{
"category": "impact",
"details": "Tampering"
},
{
"category": "exploit_status",
"details": "Publicly Disclosed:No;Exploited:No;Latest Software Release:Exploitation Less Likely"
}
],
"title": "Windows Server Update Service (WSUS) Tampering Vulnerability"
}
]
}
Loading…
Loading…
Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
Loading…
Loading…