Intel has published a security advisory today informing its customers about four new security vulnerabilities discovered in Intel CPUs, which may lead to information disclosure by allowing a malicious process to read data from another process running on the same CPU core, which is possible due to the use of buffers within the CPU core. The vulnerabilities could allow a malicious process to speculatively sample data from the said buffers, which apparently aren’t cleared when switching between processes, then interpret the contents and read data from another process that is executing on the same CPU core. This can happen when switching between kernel and userspace, host and guest, or two different userspace processes.