Multiple stack-based buffer overflows in the GNU C Library (aka glibc or libc6) before 2.23 allow context-dependent attackers to cause a denial of service (application crash) or possibly execute arbitrary code via a long argument to the (1) nan, (2) nanf, or (3) nanl function.
The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.