Windows AFD.sys CVE-2026-45601

Attacker must already have local code execution on the target Windows host as an authenticated low-privileged user (CVSS PR:L), with no user interaction required from a second party (UI:N). Exploitation is gated by AFD.sys being loaded - true for any default Windows install with networking - and by the attacker reliably winning a kernel race window (AC:H), which typically requires multi-threaded triggering code and may need retries on different CPU/scheduler configurations. The bug is not reachable over the network (AV:L), so remote unauthenticated exploitation is not possible; this is strictly a post-access privilege escalation primitive.

The CVSS 7.0 vector (AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H) describes a local, high-complexity, low-privileged-user attack with full CIA impact - characteristic of a kernel EoP that depends on winning a timing window. The High attack complexity reflects the race condition: exploitation is not deterministic and may require multiple attempts or specific scheduler conditions, dampening worm-like spread despite the high impact. No EPSS score, KEV listing, SSVC decision, or POC indicator was provided in the input, so there is no signal of active exploitation; however, AFD.sys EoP bugs have historically been weaponised by commodity malware post-disclosure, so this should be treated as a credible post-compromise escalation primitive rather than a low-priority issue. Note that the supplied tags include 'Denial Of Service', which is broader than the CVSS Availability impact alone would suggest - defenders should verify with the MSRC advisory whether a DoS-only path also exists for unprivileged callers.

An attacker who has already obtained a low-privileged foothold - for example via a phishing-delivered payload or a compromised standard user account - runs a local tool that issues tightly interleaved WinSock socket operations to race AFD.sys into freeing an object that a second thread still dereferences. By spraying the kernel pool to control the contents of the reclaimed allocation, the attacker corrupts a kernel structure to overwrite their process token or hijack execution, yielding SYSTEM. No public exploit has been identified at time of analysis.