CVE-2026-57096 is a Windows Routing and Remote Access Service (RRAS) Elevation of Privilege vulnerability caused by a heap-based buffer overflow. Microsoft rates it as High severity with a CVSS v3.1 base score of 7.8 and temporal score of 6.8. The vector is local, with low attack complexity, low privileges required, no user interaction, and unchanged scope. If successfully exploited, an attacker could gain SYSTEM privileges. Microsoft reports no public disclosure and no known exploitation; exploit code maturity is unproven. Because this is a local elevation-of-privilege issue affecting RRAS on Windows servers and clients, the main enterprise risk is from systems where untrusted local access is possible rather than from remote network exposure.

Highlights:
- CVSS scores: Base 7.8 - Temporal 6.8
- Exploit status & code maturity: Publicly Disclosed: No; Exploited: No; Exploit Code Maturity: UNPROVEN
- Impact: Elevation of Privilege; confidentiality HIGH, integrity HIGH, availability HIGH
- Exploitation likelihood: Exploitation Less Likely; vector is LOCAL with LOW attack complexity, LOW privileges required, and NO user interaction
- Severity for enterprise: High severity overall, but lower enterprise exposure than network-based vulnerabilities because exploitation requires local access on affected hosts; risk is more relevant on systems with RRAS enabled and possible untrusted local access
- Patch status: available; customer action required

Affected systems:
- Windows 10 1607
- Windows 10 1809
- Windows 10 21H2
- Windows 10 22H2
- Windows 11 24H2
- Windows 11 25H2
- Windows 11 26H1
- Windows 11 unspecified
- Windows Server 2012 R2
- Windows Server 2016
- Windows Server 2019
- Windows Server 2022
- Windows Server 2025