XMMSL2 is the second catalogue of X-ray sources found in slew data taken from the European Space Agency's (ESA) XMM-Newton observatory, and has been constructed by members of the XMM SOC and the EPIC consortium on behalf of ESA. This release uses results of work which has been carried out within the framework of the EXTraS project ("Exploring the X-ray variable and Transient Sky"), funded from the EU's Seventh Framework Programme under grant agreement no.607452. This is the first release of XMMSL2 which contains data taken between revolutions 314 and 2758. The previous catalogue was called XMMSL1_Delta6 and contained slews up to revolution 2441. The release includes two FITS files. A full catalogue (xmmsl2_total.fits.gz), containing 72352 detections found with a likelihood of DET_ML>8 and a "clean" catalogue (xmmsl2_clean.fits.gz) where all known bad sources have been removed and where the detection limit has been raised to DET_ML>10.5 in general and DET_ML>15.5 for sources found in images with a higher than usual background. Efforts have been made to identify spurious detections and 3017 have been flagged as such in the full catalogue.