The time and filter parameters in Fava prior to v1.22 are vulnerable to reflected XSS due to the lack of escaping of error messages which contained the parameters in verbatim.
{ "binaries": [ { "binary_name": "python3-fava", "binary_version": "1.14-1" } ] }
{ "binaries": [ { "binary_name": "python3-fava", "binary_version": "1.20.1-1" } ] }
{ "binaries": [ { "binary_name": "python3-fava", "binary_version": "1.30.2+dfsg-1" } ] }