GNU Patch version 2.7.6 contains an input validation vulnerability when processing patch files, specifically the EDITOR_PROGRAM invocation (using ed) can result in code execution. This attack appear to be exploitable via a patch file processed via the patch utility. This is similar to FreeBSD's CVE-2015-1418 however although they share a common ancestry the code bases have diverged over time.
The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.