Windows Kernel CVE-2026-61929

Exploitation requires an authenticated local user account with at minimum standard (low) privilege - the CVSS PR:L metric confirms this. No network-based attack vector exists; the attacker must have an interactive session or code execution on the target host (AV:L). High attack complexity (AC:H) indicates that exploitation is not straightforward: a race condition or precise memory layout condition must be reliably satisfied, which typically requires repeated attempts or environment-specific tuning. No specific non-default feature, protocol, or configuration setting has been identified as a prerequisite in available data - the vulnerability appears to reside in a core kernel code path reachable by any low-privilege process. Exploitation is limited to the specific Windows 11 and Windows Server 2025 build ranges listed; Windows 10 and earlier are not mentioned in the affected version data. A failed exploitation attempt may trigger a kernel panic (BSOD), which both exposes attacker activity and limits reliable exploitation in high-availability environments.

The CVSS 7.0 score with vector AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H signals a high-impact but locally constrained privilege escalation. The high attack complexity (AC:H) is the primary risk moderator - exploitation requires precise heap-grooming, timing control, or race-condition triggering, which significantly limits opportunistic exploitation and increases attacker capability requirements. No CISA KEV listing is present, and no public proof-of-concept has been identified at time of analysis, further tempering urgency. The tags include 'Denial of Service,' suggesting a failed exploitation attempt may crash the kernel, making unreliable exploit attempts detectable via blue screens. However, the full C/I/A impact upon success means a working exploit yields complete system compromise. Real-world priority should be moderate-to-high for organizations with untrusted local users (multi-tenant environments, VDI, shared workstations) and lower for single-user managed endpoints where physical/remote access is tightly controlled. No EPSS data was provided - exploitation probability relative to the broader vulnerability landscape cannot be quantified from available inputs.

An attacker with a standard low-privilege domain or local account on an affected Windows 11 workstation executes a crafted application that triggers a race condition between two kernel threads - for example, concurrent object close and reuse operations - causing a kernel pool allocation to be freed while a pointer remains live. The attacker times a heap-spray to reclaim the freed region with controlled data, redirecting a kernel function pointer and executing shellcode in ring-0 context to escalate to NT AUTHORITY\SYSTEM. No public proof-of-concept has been identified at time of analysis, but the technique is consistent with well-documented Windows kernel UAF exploitation tradecraft.