The yaml_parser_scan_tag_uri function in scanner.c in LibYAML before 0.1.5 performs an incorrect cast, which allows remote attackers to cause a denial of service (application crash) and possibly execute arbitrary code via crafted tags in a YAML document, which triggers a heap-based buffer overflow.
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.