CVE-2026-83699

7.8High

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

7.8High

Attack vector: Local
Complexity: Low
Privileges needed: Low
User interaction: None
Impact: Full C/I/A compromise
Weakness: CWE-121

Impact

Local attackers with low-privilege account access can escalate privileges to SYSTEM. They must already have the ability to execute code locally on the target machine.

Root cause

A stack-based buffer overflow in the Windows Client-Side Caching (CSC) Service improperly validates input size before copying data.

Affected systems

Versions not listed — check the vendor advisory.

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

Fix & remediation

Install the security update from Microsoft for CVE-2026-83699. As an interim workaround if patching must wait, disable the Offline Files (CSC) service via Group Policy or the registry.

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

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NVD description

Stack-based buffer overflow in Windows Client-Side Caching (CSC) Service allows an authorized attacker to elevate privileges locally.

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-83699

Source: nvd.nist.gov/vuln/detail/CVE-2026-83699