Windows RASMAN CVE-2026-62783

Exploitation requires a valid low-privileged local user account on the target system - the CVSS PR:L metric confirms that non-administrator credentials are sufficient; no administrative rights are needed to trigger the overflow. The attacker must be able to interact with or invoke the Windows Remote Access Connection Manager (RASMAN) service, which is present and started by default on standard Windows 10, Windows 11, and Windows Server installations - no special feature enablement or non-default configuration is required. No user interaction from another user or administrator is necessary once local access is established. Exploitation is strictly bounded to local attack surface: remote unauthenticated exploitation is not possible per AV:L, meaning an attacker must first obtain a local session (physical access, RDP, or another exploit chain providing a local shell). The limiting factors for defenders are therefore controlling who holds local logon rights and ensuring patch currency.

The CVSS 7.8 (High) score accurately represents the real-world risk profile: local attack vector (AV:L) caps the network exposure, but low attack complexity (AC:L) and low privilege requirement (PR:L) mean any local user account - including those obtained through phishing or credential reuse - is sufficient to trigger full system compromise (C:H/I:H/A:H). EPSS data was not provided in the source intelligence, preventing probabilistic exploitation forecasting. CISA KEV status is absent from the input, so active exploitation is unconfirmed. No public proof-of-concept was referenced. As a local privilege escalation, the primary threat model is post-initial-access escalation: an attacker who gains a low-privilege foothold via another vector (e.g., phishing, RDP brute-force, vulnerable application) uses this flaw to move to SYSTEM. The extraordinary breadth of affected platforms - Windows 10 through Windows 11 26H1 and Windows Server 2019 through Server 2025 - creates an extremely large exposure surface. Low attack complexity increases the likelihood of reliable exploitation once a working technique matures.

An attacker who has obtained a low-privilege local user account on an unpatched Windows host - for example, through phishing or credential compromise - crafts a malformed input to the Remote Access Connection Manager service that triggers the heap-based buffer overflow, corrupting adjacent heap structures within the elevated-privilege RASMAN process. The attacker leverages the corruption to overwrite a function pointer or control structure, redirecting execution to attacker-controlled shellcode and achieving SYSTEM-level code execution. No public exploit code was identified at time of analysis, but the low attack complexity (AC:L) indicates that reliable exploitation is achievable without significant heap-shaping or timing constraints.