徐炫 Xú Xuàn was a Tang-dynasty court compiler (著作郎 zhùzuò láng) who served in the Xiánhēng era (670–674 CE). His sole surviving work is the Wǔdài Xīnshuō 五代新說 (KR4k0014), a two-juàn collection of anecdotes about the five pre-Tang dynasties (Liang, Chen, Northern Qi, Northern Zhou, Sui). His dates are unknown; CBDB records three possible entries (ids 240454, 456081, 496903) without dates.
Name disambiguation: This 徐炫 is not to be confused with the Song-dynasty lexicographer 徐鉉 Xú Xuān (917–992), who edited the Shuōwén jiězì. Though the names are phonetically identical in Mandarin, they are different characters and different persons separated by nearly three centuries.