CVE-2026-85856

7.1High

Published 13 Oct 2026 · NVD status: Undergoing Analysis · AI triage by gemini-3.8-flash

7.1High

Attack vector: Adjacent network
Complexity: High
Privileges needed: Low
User interaction: None
Impact: Full C/I/A compromise
Weakness: CWE-122

Impact

An authenticated adjacent network attacker can execute arbitrary code on the target system. They require low-privilege access and local network adjacency to trigger the issue.

Root cause

A heap-based buffer overflow flaw exists in the Windows Internet Connection Sharing (ICS) service.

Affected systems

Versions not listed — check the vendor advisory.

CVSS v3.1 · CVSS:3.1/AV:A/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

Fix & remediation

Install the security update from Microsoft for CVE-2026-85856, or disable the Internet Connection Sharing (SharedAccess) service if patching must wait.

shell

$ Stop-Service -Name SharedAccess -PassThru | Set-Service -StartupType Disabled

AI-suggested. Run it in staging first and check it against the vendor advisory. Why?

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NVD description

Heap-based buffer overflow in Windows Internet Connection Sharing (ICS) allows an authorized attacker to execute code over an adjacent network.

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-85856

Source: nvd.nist.gov/vuln/detail/CVE-2026-85856