All compositions contained in manuscript Becker III.8.63, held by the Städtische Bibliotheken Leipzig, are in the manuscript all ascribed to Seger. Nevertheless, quite a few compositions are in other sources attributed to other composers. This fugue in c minor is one of them. In both "Museum für Orgel-Spieler Sammlung gediegener und effectvoller Orgel-Compositionen älterer und neuerer Zeit, Bd 3" (Prague, Marco Berra, 1832) and "Musica Antiqua Bohemica, Series I, Vol.12" (Prague: Artia, 1953) this fugue is ascribed to František Xaver Brixi (1732 - 1771).
Brixi was born in Prague. During his live he was organist first at St Havel, and later at the churches of St Martín, St Mikuláš and St Mary na Louži. He soon became one of the best-known composers in Prague. When he was only 27 he was appointed Kapellmeister of St Vít Cathedral, thus attaining he highest musical position in the city. He died, only 39 years old, from tuberculosis.
Brixi's music is known for fresh melodic writing, vivacious rhythm and lively bass lines and this fugue is a nice example of those characteristics.
The recording was done with the Hauptwerk software and the demo sampleset, made by Sonus Paradisi, of the Sieber organ in the Church of the Assumption of the Virgin Mary, Polná (https://www.sonusparadisi.cz/en/organs/czech/polna-sample-set.html).
Score available here: https://partitura.org/index.php/frantisek-xaver-brixi-fuga-c-moll-l-14