Windows Secure Socket Tunneling Protocol (SSTP) Remote Code Execution Vulnerability

CVE

CVE-2026-85926

Severity

Important

CVSS base score

8.1

CVSS vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C

Impact

Remote Code Execution

Exploitation detected

Not reported by MSRC

Publicly disclosed

No

Exploitability

Exploitation Less Likely

Component

Windows Secure Socket Tunneling Protocol (SSTP)

Weakness

CWE-416: Use After Free

Issued by

Microsoft

Customer action

Required: apply the update

Affected products

Windows 10 Version 1607 for 32-bit Systems, Windows 10 Version 1607 for x64-based Systems, Windows 10 Version 1809 for 32-bit Systems, Windows 10 Version 1809 for x64-based Systems, Windows 10 Version 21H2 for 32-bit Systems, Windows 10 Version 21H2 for ARM64-based Systems, Windows 10 Version 21H2 for x64-based Systems, Windows 10 Version 22H2 for 32-bit Systems, Windows 10 Version 22H2 for ARM64-based Systems, Windows 10 Version 22H2 for x64-based Systems, Windows 11 Version 23H2 for ARM64-based Systems, Windows 11 Version 23H2 for x64-based Systems, Windows 11 Version 24H2 for ARM64-based Systems, Windows 11 Version 24H2 for x64-based Systems, Windows 11 Version 25H2 for ARM64-based Systems, Windows 11 Version 25H2 for x64-based Systems, Windows 11 Version 26H1 for ARM64-based Systems, Windows 11 version 26H1 for x64-based Systems, Windows 11 Version 26H2 for ARM64-based Systems, Windows 11 Version 26H2 for x64-based Systems, Windows Server 2012, Windows Server 2012 (Server Core installation), Windows Server 2012 R2, Windows Server 2012 R2 (Server Core installation), Windows Server 2016, Windows Server 2016 (Server Core installation), Windows Server 2019, Windows Server 2019 (Server Core installation), Windows Server 2022, Windows Server 2022 (Server Core installation), Windows Server 2025, Windows Server 2025 (Server Core installation)

Updates that fix it

KB5126646: Windows Server 2025, Windows Server 2025 (Server Core installation) (restart required); KB5126651: Windows 10 Version 1809 for 32-bit Systems, Windows 10 Version 1809 for x64-based Systems, Windows Server 2019, Windows Server 2019 (Server Core installation) (restart required); KB5126653: Windows 11 Version 23H2 for ARM64-based Systems, Windows 11 Version 23H2 for x64-based Systems (restart required); KB5126655: Windows Server 2022, Windows Server 2022 (Server Core installation) (restart required); KB5126657: Windows 10 Version 21H2 for 32-bit Systems, Windows 10 Version 21H2 for ARM64-based Systems, Windows 10 Version 21H2 for x64-based Systems, Windows 10 Version 22H2 for 32-bit Systems, Windows 10 Version 22H2 for ARM64-based Systems, Windows 10 Version 22H2 for x64-based Systems (restart required); KB5126835: Windows Server 2012, Windows Server 2012 (Server Core installation) (restart required); KB5126836: Windows Server 2012 R2, Windows Server 2012 R2 (Server Core installation) (restart required); KB5126868: Windows 10 Version 1607 for 32-bit Systems, Windows 10 Version 1607 for x64-based Systems, Windows Server 2016, Windows Server 2016 (Server Core installation) (restart required); KB5127646: Windows 11 Version 26H1 for ARM64-based Systems, Windows 11 version 26H1 for x64-based Systems (restart required); KB5127648: Windows 11 Version 24H2 for ARM64-based Systems, Windows 11 Version 24H2 for x64-based Systems, Windows 11 Version 25H2 for ARM64-based Systems, Windows 11 Version 25H2 for x64-based Systems, Windows 11 Version 26H2 for ARM64-based Systems, Windows 11 Version 26H2 for x64-based Systems (restart required)

CISA KEV

Not listed in the collected catalog

EPSS

0.7%; scored 23 Oct 2026

Public exploit code

No Nuclei template listed

Published

13 Oct 2026 07:00 UTC

Last revised

13 Oct 2026 07:00 UTC

Revision note

Information published.

• MSRC advisory
• NVD
• CVE.org
• October 2026
• KB5126646
• KB5126651
• KB5126653
• KB5126655
• KB5126657
• KB5126835
• KB5126836
• KB5126868
• KB5127646
• KB5127648

Microsoft security releases

Complete at observationRead 23 Oct 2026 at 15:50 UTC

CISA KEV

Complete at observationRead 23 Oct 2026 at 15:50 UTC

FIRST EPSS

Complete at observationRead 23 Oct 2026 at 15:50 UTC

Public exploit code

Complete at observationRead 23 Oct 2026 at 15:50 UTC

Coverage describes the sources at this observation. A complete read then does not establish their current position.

1. 23 Oct 2026 · 15:51:28 UTC EPSS0.7%; scored 22 Oct 2026 → 0.7%; scored 23 Oct 2026
2. 23 Oct 2026 · 09:33:49 UTC Public exploit codeUnknown: exploit-code evidence is incomplete or retained → No Nuclei template listed
3. 23 Oct 2026 · 09:33:49 UTC CISA KEVUnknown: catalog evidence is incomplete or retained → Not listed in the collected catalog
4. 23 Oct 2026 · 09:33:49 UTC Source coverage: public-exploit-codeIncomplete → Current
5. 23 Oct 2026 · 09:33:49 UTC Source coverage: first-epssIncomplete → Current
6. 23 Oct 2026 · 09:33:49 UTC Source coverage: cisa-kevIncomplete → Current
7. 23 Oct 2026 · 09:33:49 UTC Source coverage: msrc-cvrfIncomplete → Current
8. 23 Oct 2026 · 08:31:50 UTC Public exploit codeNo Nuclei template listed → Unknown: exploit-code evidence is incomplete or retained
9. 23 Oct 2026 · 08:31:50 UTC CISA KEVNot listed in the collected catalog → Unknown: catalog evidence is incomplete or retained
10. 23 Oct 2026 · 08:31:50 UTC Source coverage: public-exploit-codeCurrent → Incomplete
11. 23 Oct 2026 · 08:31:50 UTC Source coverage: first-epssCurrent → Incomplete
12. 23 Oct 2026 · 08:31:50 UTC Source coverage: cisa-kevCurrent → Incomplete

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A day selects the latest observation by the end of that UTC day; today's selection can change until midnight. History starts when this installation records it.