Bind Filter Driver CVE-2026-83900

Requires the attacker to already have authenticated, low-privileged local code execution on the target Windows host (PR:L, AV:L) - there is no remote or network path. Exploitation further depends on triggering the use-after-free in the Bind Filter Driver (bindflt), which the high attack complexity (AC:H) indicates requires winning a race condition or achieving a specific memory-reuse timing, not a deterministic single-shot trigger. No user interaction is needed (UI:N). The combination of mandatory local foothold plus the unreliable race-dependent trigger meaningfully limits real-world exploitation to post-compromise escalation scenarios. Affected builds are specific: Windows 11 (23H2 through 26H2) and Windows Server 2025 below the fixed build numbers listed in EUVD; patched builds are not exploitable.

Signals here are consistent and point to a genuine but not emergency-grade priority. The CVSS 3.1 vector (AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H, base 7.0) describes a local privilege-escalation requiring an already-authenticated low-privileged user and a high-complexity trigger - consistent with a use-after-free (CWE-416) that depends on winning a race or precise heap state. CISA's SSVC decision data reinforces the lower urgency: Exploitation=none (no observed exploitation), Automatable=no (cannot be mass-scripted, fitting the local AV and high AC), but Technical Impact=total (full kernel compromise if achieved). No EPSS score is provided in the input, so exploitation probability cannot be quantified. This is NOT in CISA KEV and no public POC is indicated, so it is not under active exploitation. The practical reading: a credible post-compromise escalation vector worth patching in normal cycles, but not a drop-everything internet-facing emergency - its value to an attacker is as a second-stage tool after they already have a foothold, not as an initial breach vector.

An attacker who already has low-privileged code execution on a Windows host (e.g., via phishing or a compromised standard user account) runs a crafted local program that manipulates the Bind Filter Driver to trigger the use-after-free, winning the timing race required by the high attack complexity. Successful exploitation corrupts kernel memory and yields SYSTEM-level privileges, enabling full host compromise. No public exploit identified at time of analysis, and CISA SSVC lists exploitation as none.