CVE-2026-40403 · Windows Graphics Component Remote Code Execution Vulnerability

According to the CVSS metric, a successful exploitation could lead to a scope change (S:C). What does this mean for this vulnerability? This vulnerability could lead to a contained execution environment escape. Please refer to AppContainer Isolation for more information.

Heap-based buffer overflow in Windows Win32K - GRFX allows an authorized attacker to execute code locally.

According to the CVSS metric, the attack vector is local (AV:L). Why does the CVE title indicate that this is a remote code execution? The word Remote in the title refers to the location of the attacker. This type of exploit is sometimes referred to as Arbitrary Code Execution (ACE). The attack itself is carried out locally. The vulnerable endpoint is only available over the local VM interface as all external communication is blocked. This means an attacker needs to execute code from the local machine to exploit the vulnerability.

According to the CVSS metric, privileges required is low (PR:L). What does that mean for this vulnerability? Any authenticated attacker could trigger this vulnerability. It does not require admin or other elevated privileges.

How could an attacker exploit this vulnerability? An attacker can exploit this vulnerability by getting access to the local guest VM so they can attack the Host OS.