CVE-2026-96958: .NET Denial of Service Vulnerability

Ecosystem and package	Affected range	First fixed version	Evidence
NuGetSystem.Security.Cryptography.Xml	`ECOSYSTEM: introduced 10.0.0; fixed 10.0.13`	`10.0.13`	OSV record ↗aggregator derived · 13 Oct 2026
NuGetSystem.Security.Cryptography.Xml	`ECOSYSTEM: introduced 11.0.0-preview.1; fixed 11.0.0-rc.2`	`11.0.0-rc.2`	OSV record ↗aggregator derived · 13 Oct 2026
NuGetSystem.Security.Cryptography.Xml	`ECOSYSTEM: introduced 8.0.0; fixed 8.0.5`	`8.0.5`	OSV record ↗aggregator derived · 13 Oct 2026
NuGetSystem.Security.Cryptography.Xml	`ECOSYSTEM: introduced 9.0.0; fixed 9.0.21`	`9.0.21`	OSV record ↗aggregator derived · 13 Oct 2026
nugetSystem.Security.Cryptography.Xml	`>= 10.0.0, <= 10.0.12`	`10.0.13`	GitHub advisory ↗upstream repository advisory · 13 Oct 2026
nugetSystem.Security.Cryptography.Xml	`>= 11.0.0-preview.1, <= 11.0.0-rc.1`	`11.0.0-rc.2`	GitHub advisory ↗upstream repository advisory · 13 Oct 2026
nugetSystem.Security.Cryptography.Xml	`>= 8.0.0, <= 8.0.4`	`8.0.5`	GitHub advisory ↗upstream repository advisory · 13 Oct 2026
nugetSystem.Security.Cryptography.Xml	`>= 9.0.0, <= 9.0.20`	`9.0.21`	GitHub advisory ↗upstream repository advisory · 13 Oct 2026

Recommended actionWithin 7 days

High technical severity; prioritise exposed affected systems while verifying vendor guidance.

Patch available

What, why and how

Inefficient algorithmic complexity in .NET allows an unauthorized attacker to deny service over a network.

What

Inefficient algorithmic complexity in .NET allows an unauthorized attacker to deny service over a network.

Why

An algorithm in a product has an inefficient worst-case computational complexity that may be detrimental to system performance and can be triggered by an attacker, typically using crafted manipulations that ensure that the worst case is being reached.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.

What

Inefficient algorithmic complexity in .NET allows an unauthorized attacker to deny service over a network.

Why

How

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation

Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.

No confirmed evidence

No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.

Public PoC / exploit material

Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.

None recorded

No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.

Likely attack path: a network path → Inefficient Algorithmic Complexity → cause the confidentiality, integrity or availability impact described by the vendor
Attack surface: Network
Privileges required: None: unauthenticated exploitation is possible
User interaction: None
Attack complexity: Low: no specialised conditions are recorded
Security boundary: Unchanged: impact remains within the vulnerable component's security authority
Weakness ? CWE means Common Weakness Enumeration: a standard category for the underlying weakness.: CWE-407 ↗
CWE-407: Inefficient Algorithmic Complexity. An algorithm in a product has an inefficient worst-case computational complexity that may be detrimental to system performance and can be triggered by an attacker, typically using crafted manipulations that ensure that the worst case is being reached.
CVSS vector ? CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.: 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
Common Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.
AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRNonePrivileges required: The attacker does not need an account or existing privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CNoneConfidentiality impact: No direct loss is represented by this metric.INoneIntegrity impact: No direct loss is represented by this metric.AHighAvailability impact: A successful attack can cause a major loss.
Post-exploitation / living off the land: No specific living-off-the-land technique is confirmed in the structured sources. Monitor normal administration tools for activity inconsistent with the affected service's baseline.

NetworkUnauthenticatedCWE-407

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

ENISA EUVD · EUVD-2026-100279Official EUVD mapping

Inefficient algorithmic complexity in .NET allows an unauthorized attacker to deny service over a network.

Official EUVD record ↗

BSI · German · WID-SEC-2026-3893Microsoft Entwicklerwerkzeuge: Mehrere Schwachstellen

Ein Angreifer kann mehrere Schwachstellen in Microsoft .NET Framework, Microsoft .NET, Microsoft ASP.NET, Microsoft Visual Studio 2022, Microsoft Visual Studio 2026, Microsoft Visual Studio Code, Microsoft SysInternals und Microsoft PowerShell ausnutzen, um seine Privilegien zu erhöhen, um Code auszuführen, um Informationen offenzulegen, um Sicherheitsmechanismen zu umgehen und um einen Denial of Service Zustand herbeizuführen.

Official advisory ↗

CERT-FR · French · CERTFR-2026-AVI-1313Avis du CERT-FR

rité Microsoft .Net CVE-2026-96231 du 13 octobre 2026 Bulletin de sécurité Microsoft .Net CVE-2026-96232 du 13 octobre 2026 Bulletin de sécurité Microsoft .Net CVE-2026-96233 du 13 octobre 2026 Bulletin de sécurité Microsoft .Net CVE-2026-96234 du 13 octobre 2026 Bulletin de sécurité Microsoft .Net CVE-2026-96235 du 13 octobre 2026 Bulletin de sécurité Microsoft .Net CVE-2026-96236 du 13 octobre 2026 Bulletin de sécurité Microsoft .Net CVE-2026-96237 du 13 octobre 2026 Bulletin de sécurité Microsoft .Net CVE-2026-96238 du 13 octobre 2026 Bulletin de sécurité Microsoft .Net CVE-2026-96957 du 13 octobre 2026 Bulletin de sécurité Microsoft .Net CVE-2026-96958 du 13 octobre 2026 Bulletin de sécurité Microsoft .Net CVE-2026-96959 du 13 octobre 2026 Bulletin de sécurité Microsoft .Net CVE-2026-96960 du 13 octobre 2026 Bulletin de sécurité Microsoft .Net CVE-2026-97788 du 13 octobre 2026 Bulletin de sécurité Microsoft .Net CVE-2026-97801 du 13 octobre 2026 Une gestion de version détaillée se trouve à la fin de ce document. Risques Atteinte à l'intégrité des données Atteinte à la confidentialité des données Contournement de la politique de sécurité Déni de service à distance Exécution de code arbitraire à distance Élévation de privilèges Systèmes affectés .NET 10.0 installé sur Linux versions antérieu

Official advisory ↗

CERT-FR · French · CERTFR-2026-AVI-1316Avis du CERT-FR

CVE-2026-96234 du 13 octobre 2026 Bulletin de sécurité Microsoft CVE-2026-96235 du 13 octobre 2026 Bulletin de sécurité Microsoft CVE-2026-96236 du 13 octobre 2026 Bulletin de sécurité Microsoft CVE-2026-96237 du 13 octobre 2026 Bulletin de sécurité Microsoft CVE-2026-96238 du 13 octobre 2026 Bulletin de sécurité Microsoft CVE-2026-96251 du 13 octobre 2026 Bulletin de sécurité Microsoft CVE-2026-96303 du 13 octobre 2026 Bulletin de sécurité Microsoft CVE-2026-96943 du 13 octobre 2026 Bulletin de sécurité Microsoft CVE-2026-96956 du 13 octobre 2026 Bulletin de sécurité Microsoft CVE-2026-96957 du 13 octobre 2026 Bulletin de sécurité Microsoft CVE-2026-96958 du 13 octobre 2026 Bulletin de sécurité Microsoft CVE-2026-96959 du 13 octobre 2026 Bulletin de sécurité Microsoft CVE-2026-96960 du 13 octobre 2026 Bulletin de sécurité Microsoft CVE-2026-97755 du 13 octobre 2026 Bulletin de sécurité Microsoft CVE-2026-97782 du 13 octobre 2026 Bulletin de sécurité Microsoft CVE-2026-97783 du 13 octobre 2026 Une gestion de version détaillée se trouve à la fin de ce document. Risques Atteinte à l'intégrité des données Atteinte à la confidentialité des données Contournement de la politique de sécurité Déni de service à distance Exécution de code arbitraire à distance Élévation de privilèges Systèmes affectés H

Official advisory ↗

CSIRT Italia · Italian · aggiornamenti-mensili-microsoft-25Aggiornamenti Mensili Microsoft

nuova finestra - - CVE-2026-97012 : apre una nuova finestra - - CVE-2026-97011 : apre una nuova finestra - - CVE-2026-97010 : apre una nuova finestra - - CVE-2026-97009 : apre una nuova finestra - - CVE-2026-97008 : apre una nuova finestra - - CVE-2026-97007 : apre una nuova finestra - - CVE-2026-97004 : apre una nuova finestra - - CVE-2026-97003 : apre una nuova finestra - - CVE-2026-97001 : apre una nuova finestra - - CVE-2026-96997 : apre una nuova finestra - - CVE-2026-96996 : apre una nuova finestra - - CVE-2026-96995 : apre una nuova finestra - - CVE-2026-96960 : apre una nuova finestra - - CVE-2026-96959 : apre una nuova finestra - - CVE-2026-96958 : apre una nuova finestra - - CVE-2026-96957 : apre una nuova finestra - - CVE-2026-96956 : apre una nuova finestra - - CVE-2026-96953 : apre una nuova finestra - - CVE-2026-96952 : apre una nuova finestra - - CVE-2026-96951 : apre una nuova finestra - Presente CVE-2026-96950 : apre una nuova finestra - - CVE-2026-96949 : apre una nuova finestra - - CVE-2026-96947 : apre una nuova finestra - - CVE-2026-96946 : apre una nuova finestra - - CVE-2026-96945 : apre una nuova finestra - - CVE-2026-96943 : apre una nuova finestra - - CVE-2026-96940 : apre una nuova finestra - - CVE-2026-96939 : apre una nuova finestra - - CVE-2026-96937 : apre una n

Official advisory ↗

NCSC-NL · Dutch · NCSC-2026-0426Kwetsbaarheden verholpen in Microsoft Developer Tools

Een kwaadwillende kan aanvallen uitvoeren die kunnen leiden tot de categoriën schade zoals weergegeven in de onderstaande tabellen. .NET: |------------------|------|-------------------------------------| | CVE-ID | CVSS | Impact | |------------------|------|-------------------------------------| | CVE-2026-58280 | 7.50 | Denial-of-Service | | CVE-2026-66822 | 5.90 | Toegang tot gevoelige gegevens | | CVE-2026-69651 | 7.50 | Denial-of-Service | | CVE-2026-70161 | 7.30 | Verkrijgen van verhoogde rechten | | CVE-2026-70165 | 6.70 | Verkrijgen van verhoogde rechten | | CVE-2026-70174 | 8.80 | Uitvoeren van willekeurige code | | CVE-2026-70190 | 7.30 | Verkrijgen van verhoogde rechten | | CVE-2026-70197 | 8.10 | Uitvoeren van willekeurige code | | CVE-2026-83520 | 8.80 | Uitvoeren van willekeurige code | | CVE-2026-84008 | 7.50 | Denial-of-Service | | CVE-2026-87697 | 8.80 | Uitvoeren van willekeurige code, | | CVE-2026-96224 | 8.80 | Uitvoeren van willekeurige code | | CVE-2026-96225 | 7.80 | Verkrijgen van verhoogde rechten | | CVE-2026-96229 | 6.50 | Toegang tot gevoelige gegevens | | CVE-2026-96231 | 7.80 | Verkrijgen van verhoogde rechten | | CVE-2026-96232 | 7.50 | Toegang tot gevoelige gegevens | | CVE-2026-96234 | 5.30 | Toegang tot gevoelige gegevens | | CVE-2026-96235 | 8.80 | Uitvoeren van willekeurige code | | CVE-2026-96237 | 7.50 | Uitvoeren van willekeurige code | | CVE-2026-96238 | 6.50 | Omzeilen van beveiligingsmaatregel | | CVE-2026-96957 | 8.80 | Omzeilen van beveiligingsmaatregel | | CVE-2026-96958 | 7.50 | Denial-of-Service | | CVE-2026-96959 | 7.50 | Denial-of-Service | | CVE-2026-96960 | 7.50 | Denial-of-Service | |------------------|------|-------------------------------------| Visual Studio Code: |------------------|------|-------------------------------------| | CVE-ID | CVSS | Impact | |------------------|------|-------------------------------------| | CVE-2026-102229 | 6.80 | Toegang tot gevoelige gegevens | | CVE-2026-102230 | 7.40 | Toegang tot gevoelige gegevens | | CVE-2026-102231 | 7.70 | Omzeilen van beveiligingsmaatregel | | CVE-2026-102232 | 7.00 | Omzeilen van beveiligingsmaatregel | | CVE-2026-102233 | 7.80 | Omzeilen van beveiligingsmaatregel | | CVE-2026-102234 | 7.40 | Omzeilen van beveiligingsmaatregel | | CVE-2026-102235 | 8.80 | Uitvoeren van willekeurige code | | CVE-2026-102238 | 9.60 | Uitvoeren van willekeurige code | | CVE-2026-102851 | 6.10 | Omzeilen van beveiligingsmaatregel | | CVE-2026-69370 | 8.80 | Uitvoeren van willekeurige code | | CVE-2026-70098 | 8.80 | Uitvoeren van willekeurige code | |------------------|------|-------------------------------------| ASP.NET Core: |------------------|------|-------------------------------------| | CVE-ID | CVSS | Impact | |------------------|------|-------------------------------------| | CVE-2026-102870 | 8.80 | Uitvoeren van willekeurige code | | CVE-2026-70159 | 7.50 | Denial-of-Service | | CVE-2026-70175 | 8.10 | Verkrijgen van verhoogde rechten | | CVE-2026-70179 | 7.50 | Verkrijgen van verhoogde rechten | | CVE-2026-70181 | 7.50 | Denial-of-Service | | CVE-2026-70183 | 7.50 | Verkrijgen van verhoogde rechten | | CVE-2026-70186 | 7.50 | Denial-of-Service | | CVE-2026-70188 | 9.10 | Omzeilen van beveiligingsmaatregel | | CVE-2026-70196 | 5.90 | Denial-of-Service | | CVE-2026-88092 | 9.40 | | | CVE-2026-96230 | 8.80 | Uitvoeren van willekeurige code | | CVE-2026-96233 | 7.50 | Denial-of-Service | | CVE-2026-96236 | 7.50 | Denial-of-Service | |------------------|------|-------------------------------------| Visual Studio Tools for Applications and SQL Server Management Studio: |------------------|------|-------------------------------------| | CVE-ID | CVSS | Impact | |------------------|------|-------------------------------------| | CVE-2026-103572 | 8.80 | Uitvoeren van willekeurige code | |------------------|------|-------------------------------------| Windows AppX Deployment Extensions: |------------------|------|-------------------------------------| | CVE-ID | CVSS | Impact | |------------------|------|-------------------------------------| | CVE-2026-69945 | 8.80 | Verkrijgen van verhoogde rechten | |------------------|------|-------------------------------------| .NET Framework: |------------------|------|-------------------------------------| | CVE-ID | CVSS | Impact | |------------------|------|-------------------------------------| | CVE-2026-108398 | 8.80 | Omzeilen van beveiligingsmaatregel | | CVE-2026-70007 | 8.80 | Uitvoeren van willekeurige code | | CVE-2026-70035 | 8.80 | Uitvoeren van willekeurige code | | CVE-2026-70194 | 6.50 | Omzeilen van beveiligingsmaatregel | | CVE-2026-85363 | 8.80 | Verkrijgen van verhoogde rechten | |------------------|------|-------------------------------------| Windows AppX Deployment Service: |------------------|------|-------------------------------------| | CVE-ID | CVSS | Impact | |------------------|------|-------------------------------------| | CVE-2026-69905 | 5.50 | | | CVE-2026-69914 | 5.50 | Toegang tot gevoelige gegevens | | CVE-2026-69969 | 4.70 | Toegang tot gevoelige gegevens | | CVE-2026-69979 | 5.50 | Omzeilen van beveiligingsmaatregel | | CVE-2026-85849 | 7.80 | Verkrijgen van verhoogde rechten | | CVE-2026-85934 | 7.00 | Verkrijgen van verhoogde rechten | |------------------|------|-------------------------------------| .NET and Visual Studio: |------------------|------|-------------------------------------| | CVE-ID | CVSS | Impact | |------------------|------|-------------------------------------| | CVE-2026-102869 | 8.80 | Verkrijgen van verhoogde rechten, | |------------------|------|-------------------------------------|

Official advisory ↗

Patch and workaround

Operational remediation based on structured source evidence.

Status ? Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.: Patch available
Affected: Microsoft .NET Framework 3.5: 3.5.0 < 2.0.50727.9188 AND 3.0.30729.9171
Microsoft .NET Framework 3.5 AND 4.6.2/4.7/4.7.1/4.7.2: 3.0.0.0 < 2.0.50727.8987 AND 3.0.30729.8982 AND 4.7.4150.0
Microsoft .NET Framework 3.5 AND 4.7.2: 4.7.0 < 2.0.50727.9073 AND 3.0.30729.9070 AND 4.7.4150.0
Microsoft .NET Framework 3.5 AND 4.8: 4.8.0 < 2.0.50727.9073 AND 3.0.30729.9070 AND 4.8.4811.0
Microsoft .NET Framework 3.5 AND 4.8.1: 4.8.1 < 2.0.50727.9188 AND 3.0.30729.9171 AND 4.8.9363.0
Microsoft .NET Framework 4.6.2/4.7/4.7.1/4.7.2: 4.7.0 < 4.7.4150.0
Microsoft .NET Framework 4.8: 4.8.0 < 4.8.4811.0
Microsoft .NET Framework 4.8.1: 4.8.0.0 < 4.8.9363.0
System.Security.Cryptography.Xml: 10.0.0 < 10.0.13
Fixed: An authoritative update reference is available, but the fixed version is not recorded in the structured CVE fields. Check the linked vendor advisory for the applicable release.
Action: Review the linked authoritative reference and apply the recorded fixed release appropriate to the affected product branch.
Workaround: No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.

Official vendor articles12 stored documents

Linked articles are downloaded and versioned as source evidence. A CVE mention or approved update relationship does not, by itself, verify a fix for every product branch.

October 13, 2026—KB5126868 (OS Build 14393.9612) | Microsoft Support →Original publisher ↗Searchable text snapshot · Captured 14 Oct 2026October 13, 2026—KB5126868 (OS Build 14393.9612) Applies To Windows Server 2016, all editions Win 10 Ent LTSB 2016 Win 10 IoT Ent LTSB 2016 Important Free support for Windows 10 Enterprise LTSB 2016 and Windows 10 IoT Enterprise 2016 LTSB ends on October 13, 2026. Free support for Windows Server 2016 ends soon. To lea
October 13, 2026-Security and Quality Rollup for .NET Framework 3.5 for Windows Server 2012 (KB5127660) | Microsoft Support →Original publisher ↗Searchable text snapshot · Captured 14 Oct 2026October 13, 2026-Security and Quality Rollup for .NET Framework 3.5 for Windows Server 2012 (KB5127660) Applies To .NET Note Applies to: Microsoft .NET Framework 3.5 Important The installation of this Extended Security Update (ESU) might fail when you try to install it on an Azure Arc-enabled device that is running W
October 13, 2026-Security and Quality Rollup for .NET Framework 3.5 for Windows Server 2012 R2 (KB5127664) | Microsoft Support →Original publisher ↗Searchable text snapshot · Captured 14 Oct 2026October 13, 2026-Security and Quality Rollup for .NET Framework 3.5 for Windows Server 2012 R2 (KB5127664) Applies To .NET Note Applies to: Microsoft .NET Framework 3.5 Important The installation of this Extended Security Update (ESU) might fail when you try to install it on an Azure Arc-enabled device that is runnin
October 13, 2026-KB5127666 Cumulative Update for .NET Framework 3.5 and 4.7.2 for Windows 10, version 1809 and Windows Server 2019 | Microsoft Support →Original publisher ↗Searchable text snapshot · Captured 14 Oct 2026October 13, 2026-KB5127666 Cumulative Update for .NET Framework 3.5 and 4.7.2 for Windows 10, version 1809 and Windows Server 2019 Applies To .NET Note Release Date: October 13, 2026 Version: .NET Framework 3.5 and 4.7.2 The October 13, 2026 update for Windows 10, version 1809 and Windows Server 2019 includes secu
October 13, 2026-Security and Quality Rollup for .NET Framework 4.6.2, 4.7, 4.7.1, 4.7.2 for Windows Server 2012 (KB5127667) | Microsoft Support →Original publisher ↗Searchable text snapshot · Captured 14 Oct 2026October 13, 2026-Security and Quality Rollup for .NET Framework 4.6.2, 4.7, 4.7.1, 4.7.2 for Windows Server 2012 (KB5127667) Applies To .NET Note Applies to: Microsoft .NET Framework 4.6.2 Microsoft .NET Framework 4.7 Microsoft .NET Framework 4.7.1 Microsoft .NET Framework 4.7.2 Important The installation of this Ext
October 13, 2026-KB5127684 Cumulative Update for .NET Framework 4.8 for Windows 10, version 1607 and Windows Server 2016 | Microsoft Support →Original publisher ↗Searchable text snapshot · Captured 14 Oct 2026October 13, 2026-KB5127684 Cumulative Update for .NET Framework 4.8 for Windows 10, version 1607 and Windows Server 2016 Applies To .NET Note Release Date: October 13, 2026 Version: .NET Framework 4.8 The October 13, 2026 update for Windows 10, version 1607 and Windows Server 2016 includes security and cumulative
October 13, 2026-KB5127685 Cumulative Update for .NET Framework 3.5 and 4.8 for Windows 10, version 1809 and Windows Server 2019 | Microsoft Support →Original publisher ↗Searchable text snapshot · Captured 14 Oct 2026October 13, 2026-KB5127685 Cumulative Update for .NET Framework 3.5 and 4.8 for Windows 10, version 1809 and Windows Server 2019 Applies To .NET Note Release Date: October 13, 2026 Version: .NET Framework 3.5 and 4.8 The October 13, 2026 update for Windows 10, version 1809 and Windows Server 2019 includes security
October 13, 2026-Security and Quality Rollup for .NET Framework 4.8 for Windows Server 2012 (KB5127686) | Microsoft Support →Original publisher ↗Searchable text snapshot · Captured 14 Oct 2026October 13, 2026-Security and Quality Rollup for .NET Framework 4.8 for Windows Server 2012 (KB5127686) Applies To .NET Note Applies to: Microsoft .NET Framework 4.8 Important The installation of this Extended Security Update (ESU) might fail when you try to install it on an Azure Arc-enabled device that is running W
October 13, 2026-KB5127687 Cumulative Update for .NET Framework 3.5 and 4.8 for Windows Server 2022 | Microsoft Support →Original publisher ↗Searchable text snapshot · Captured 14 Oct 2026October 13, 2026-KB5127687 Cumulative Update for .NET Framework 3.5 and 4.8 for Windows Server 2022 Applies To .NET Note Release Date: October 13, 2026 Version: .NET Framework 3.5 and 4.8 The October 13, 2026 update for Windows Server 2022 includes security and cumulative reliability improvements in .NET Framework
October 13, 2026-Security and Quality Rollup for .NET Framework 4.8 for Windows Server 2012 R2 (KB5127688) | Microsoft Support →Original publisher ↗Searchable text snapshot · Captured 14 Oct 2026October 13, 2026-Security and Quality Rollup for .NET Framework 4.8 for Windows Server 2012 R2 (KB5127688) Applies To .NET Note Applies to: Microsoft .NET Framework 4.8 Important The installation of this Extended Security Update (ESU) might fail when you try to install it on an Azure Arc-enabled device that is runnin
October 13, 2026-KB5127689 Cumulative Update for .NET Framework 3.5 and 4.8.1 for Windows 10 Version 21H2 and Windows 10 Version 22H2 | Microsoft Support →Original publisher ↗Searchable text snapshot · Captured 14 Oct 2026October 13, 2026-KB5127689 Cumulative Update for .NET Framework 3.5 and 4.8.1 for Windows 10 Version 21H2 and Windows 10 Version 22H2 Applies To .NET Note Release Date: October 13, 2026 Version: .NET Framework 3.5 and 4.8.1 The October 13, 2026 update for Windows 10 Version 21H2 and Windows 10 Version 22H2 include
October 13, 2026-KB5127690 Cumulative Update for .NET Framework 3.5 and 4.8.1 for Windows 11, version 24H2, Windows 11, version 25H2 and Microsoft server operating system 24H2 | Microsoft Support →Original publisher ↗Searchable text snapshot · Captured 14 Oct 2026October 13, 2026-KB5127690 Cumulative Update for .NET Framework 3.5 and 4.8.1 for Windows 11, version 24H2, Windows 11, version 25H2 and Microsoft server operating system 24H2 Applies To .NET Note Release date: October 13, 2026 Version: .NET Framework 3.5 and 4.8.1 The October 13, 2026 update for Windows 11, version 2

Evidence and provenance

Published 13 Oct 2026 · Last source change 14 Oct 2026, 17:59 UTC · CWE-407 · Inefficient Algorithmic Complexity

CVE recordCVE.org · 5.2

CVSS sourceCNA

EPSS source

The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.

FIRST · tracked since 2026-10-14

European sourceENISA EUVD · EUVD-2026-100279

Product sourceCNA

Remediation sourceCVE/CNA references

CWE sourceOther authority

NVD statusNVD awaiting enrichment

Core structured fields are present and their contributing authorities are shown above.

Material change intelligence

What changed after publication

View recent updates ↗

14 Oct 2026, 17:59 UTC
Vendor guidanceAuthoritative vendor guidance changed: removed remediation: acn.gov.it/aggiornamenti-mensili-microsoft-25.
Before
remediation: acn.gov.it/aggiornamenti-mensili-microsoft-25
After
no authoritative guidance recorded
CNA ↗
14 Oct 2026, 17:59 UTC
Remediation statusRemediation status changed from Mitigation available to Awaiting fix.
Before
Mitigation available
After
Awaiting fix
CNA ↗
14 Oct 2026, 17:05 UTC
Vendor guidanceAuthoritative vendor guidance changed: removed remediation: acn.gov.it/aggiornamenti-mensili-microsoft-25.
Before
remediation: acn.gov.it/aggiornamenti-mensili-microsoft-25
After
no authoritative guidance recorded
CNA ↗
14 Oct 2026, 17:05 UTC
Remediation statusRemediation status changed from Mitigation available to Awaiting fix.
Before
Mitigation available
After
Awaiting fix
CNA ↗
14 Oct 2026, 08:49 UTC
Remediation statusRemediation status changed from Awaiting fix to Mitigation available.
Before
Awaiting fix
After
Mitigation available
CSIRT Italia ↗
14 Oct 2026, 03:43 UTC
ENISA EUVD mappingEUVD-2026-100279 was added to the official ENISA EUVD mapping for this CVE.
Before
not recorded
After
{"euvdId":"EUVD-2026-100279"}
ENISA EUVD ↗
13 Oct 2026, 19:41 UTC
CVSS scoreCVSS vector changed while the displayed base score remained 7.5.
Before
7.5 (CVSS 3.1 · CNA · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)
After
7.5 (CVSS 3.1 · CNA · 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)
CNA ↗
13 Oct 2026, 19:27 UTC
Catalogue recordCVE added to the BlackTree catalogue.
CNA ↗

2026-10-13CVE published

2026-10-14Remediation guidance recorded

ENISA EUVD · EUVD-2026-100279↗CSIRT Italia remediation guidance↗CVE authority or vendor reference↗Official CVE record (CNA and ADP data)↗NVD record↗

Technical terms and abbreviations used in this report

CVE: Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS: Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS: Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE: Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA: CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP: Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD: National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT: A computer security incident response team that publishes warnings or coordinates incident response.
PoC: Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF: Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL: Living off the land: abuse of legitimate tools or system functions during an attack.

.NET Denial of Service Vulnerability

Published severity in operational context

Evidence used

Compensating controls

Verification

National CERT insights
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CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

ENISA European Vulnerability Database

EUVD-2026-100279

What, why and how

Exploit reality and attack path

Official authority intelligence

Patch and workaround

Evidence and provenance

What changed after publication