CVE-2026-18629 is a vulnerability in a GPU compiler process triggered by loading a web page containing unusual GPU shader code. The flaw arises from integer overflow during arithmetic on shader-derived values, causing incorrect memory allocation size calculations. This can lead to memory allocation failure and, if not properly handled, a NULL pointer dereference causing the compiler process to crash. On some platforms where the compiler runs with system privileges, this crash could enable further exploits or system instability.