Windows Kernel CVE-2026-83913

Exploitation requires the attacker to already have local, authenticated access to the target Windows system with at least low-level privileges (PR:L) - for example an interactive or sandboxed low-privileged account able to run code - after which no user interaction (UI:N) and no special timing or configuration (AC:L) is needed to trigger the kernel use-after-free. There is no remote or network vector (AV:L), so purely external, unauthenticated attackers cannot exploit this directly; it functions as a local privilege-escalation primitive that must be chained with an initial-access method. The limiting factors are the requirement for pre-existing code execution on the host and the specific unpatched Windows kernel build ranges listed in the EUVD data (e.g. Windows 11 24H2 below 10.0.26100.9711, Windows Server 2025 below 10.0.26100.33650, Windows 10 22H2 below the fixed build).

This is a locally-exploitable privilege-escalation flaw: the CVSS 3.1 vector (AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H, base 7.8 HIGH) indicates an attacker who already has low-privileged, authenticated access to the host can reliably (AC:L, no user interaction) achieve full confidentiality, integrity and availability impact - consistent with kernel-level code execution via a use-after-free (CWE-416). The signals are internally consistent but point to a measured rather than emergency priority: CISA's SSVC decision data lists Exploitation=none and Automatable=no, meaning no observed exploitation and no reliable mass-automation, even though Technical Impact=total aligns with the HIGH CVSS. No EPSS score, no CISA KEV listing, and no public POC were provided, so there is no exploit evidence to date - this is a post-authentication local EoP, not a remotely wormable issue. The realistic risk is that this becomes a second-stage tool: an attacker who already has a foothold (malware, phished user, compromised low-priv account) uses it to reach SYSTEM. Because the affected product is Windows itself, patch prioritization should still be treated seriously despite the absence of active-exploitation signals. Note the 'Denial Of Service' tag conflicts somewhat with the stated impact - the advisory describes privilege elevation, not a DoS primitive - so treat the DoS framing as secondary to the EoP classification.

An attacker who has already gained low-privileged local access to a Windows host - for example through a phishing payload, a compromised standard user account, or a sandboxed application - runs a crafted program that triggers the use-after-free in the Windows Kernel to corrupt kernel memory and elevate to SYSTEM. Because AC:L and UI:N, the exploit requires no user interaction and no special timing once the attacker can execute code locally. No public exploit code was identified at time of analysis, so this scenario is inferred from the CVSS vector and CWE-416 rather than a known POC.