There are 2 open security issues in buster.
2 issues left for the package maintainer to handle:
libaspell.a in GNU Aspell before 0.60.8 has a stack-based buffer over-read in acommon::unescape in common/getdata.cpp via an isolated \ character.
libaspell.a in GNU Aspell before 0.60.8 has a buffer over-read for a string ending with a single '\0' byte, if the encoding is set to ucs-2 or ucs-4 outside of the application, as demonstrated by the ASPELL_CONF environment variable.
You can find information about how to handle these issues in the security team's documentation.