An issue was discovered in Xen through 4.9.x allowing x86 HVM guest OS users to obtain sensitive information from the host OS (or an arbitrary guest OS) because intercepted I/O operations can cause a write of data from uninitialized hypervisor stack memory.
| Software | From | Fixed in |
|---|---|---|
| xen / xen | 4.9.0 | 4.9.0.x |