.NET Remote Code Execution Vulnerability

CVE

CVE-2026-70197

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

.NET

Weakness

CWE-787: Out-of-bounds Write

Issued by

Microsoft

Customer action

Required: apply the update

Affected products

.NET 10.0 installed on Windows, .NET 11.0 installed on Windows, .NET 8.0 installed on Windows, .NET 9.0 installed on Windows, Microsoft Visual Studio 2022 version 17.14, Microsoft Visual Studio 2026 version 18.10

Updates that fix it

KB5130034: .NET 8.0 installed on Windows; KB5130035: .NET 9.0 installed on Windows; KB5130036: .NET 10.0 installed on Windows

CISA KEV

Not listed in the collected catalog

EPSS

0.7%; scored 21 Oct 2026

Public exploit code

No Nuclei template listed

Published

13 Oct 2026 07:00 UTC

Last revised

19 Oct 2026 07:00 UTC

Revision note

Microsoft is aware that the vulnerability for which this CVE was assigned has not been addressed. We are working to prepare and test a complete mitigation. We will update this document when there is more information.

• MSRC advisory
• NVD
• CVE.org
• October 2026
• KB5130034
• KB5130035
• KB5130036

Microsoft security releases

Complete at observationRead 21 Oct 2026 at 21:46 UTC

CISA KEV

Complete at observationRead 21 Oct 2026 at 21:46 UTC

FIRST EPSS

Complete at observationRead 21 Oct 2026 at 21:46 UTC

Public exploit code

Complete at observationRead 21 Oct 2026 at 21:46 UTC

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

1. 21 Oct 2026 · 21:47:24 UTC EPSS0.7%; scored 20 Oct 2026 → 0.7%; scored 21 Oct 2026
2. 20 Oct 2026 · 20:53:31 UTC EPSS0.7%; scored 19 Oct 2026 → 0.7%; scored 20 Oct 2026
3. 20 Oct 2026 · 06:50:25 UTC Revision noteUpdated an acknowledgement. This is an informational change only. → Microsoft is aware that the vulnerability for which this CVE was assigned has not been addressed. We are working to prepare and test a complete mitigation. We will update this document when there is more information.
4. 20 Oct 2026 · 06:50:25 UTC Last revised16 Oct 2026 07:00 UTC → 19 Oct 2026 07:00 UTC
5. 19 Oct 2026 · 15:12:40 UTC EPSS0.7%; scored 18 Oct 2026 → 0.7%; scored 19 Oct 2026
6. 18 Oct 2026 · 14:54:30 UTC EPSS0.7%; scored 16 Oct 2026 → 0.7%; scored 18 Oct 2026
7. 18 Oct 2026 · 14:54:30 UTC Link: October 2026/security?release=2026-Oct#cves
8. 16 Oct 2026 · 16:13:25 UTC Revision noteUpdated the Security Updates table to add KB article links for .NET 11.0 and download and KB article links for Microsoft Visual Studio. This is an informational change only; the fixed builds are unchanged. → Updated an acknowledgement. This is an informational change only.
9. 16 Oct 2026 · 16:13:25 UTC Last revised15 Oct 2026 07:00 UTC → 16 Oct 2026 07:00 UTC
10. 16 Oct 2026 · 16:13:25 UTC EPSS0.7%; scored 15 Oct 2026 → 0.7%; scored 16 Oct 2026
11. 15 Oct 2026 · 21:30:54 UTC Revision noteInformation published. → Updated the Security Updates table to add KB article links for .NET 11.0 and download and KB article links for Microsoft Visual Studio. This is an informational change only; the fixed builds are unchanged.
12. 15 Oct 2026 · 21:30:54 UTC Last revised13 Oct 2026 07:00 UTC → 15 Oct 2026 07:00 UTC

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