CVE-2026-83498

CVE-2026-83498 is an untrusted pointer dereference (CWE-822) in the Virtualization-Based Security (VBS) Enclave component of Microsoft Windows. An authorized local attacker, meaning someone who already holds low-privileged code execution on the machine, can cause the enclave to dereference attacker-controlled pointers with no user interaction required. Successful exploitation breaks the VBS enclave trust boundary and elevates the attacker's privileges locally, with high impact on confidentiality, integrity, and availability (CVSS 3.1: 7.8). All Windows editions that ship the VBS Enclave feature are in scope, but the source data does not enumerate specific vulnerable builds, so defenders should consult Microsoft's advisory for the exact affected-product matrix. No public proof-of-concept, CISA KEV listing, or confirmed in-the-wild exploitation is known, EPSS assigns only a 0.3% probability of exploitation within 30 days, and fixes shipped in Microsoft's September 2026 Patch Tuesday release, which addressed 974 vulnerabilities including 2 zero-days (this CVE is not confirmed to be one of the actively exploited ones).

What to do: Apply Microsoft's September 2026 Patch Tuesday cumulative updates to affected Windows systems, prioritizing multi-user hosts, jump servers, and endpoints where untrusted or low-privileged users can execute code. Verify VBS status via System Information (msinfo32) and confirm the September 2026 update is installed using the fixed-build details in Microsoft's advisory. No workaround is documented, and with no public PoC or in-the-wild exploitation known, routine patch cadence is reasonable for isolated single-user systems.