A sensor for determining at least one property of a measuring gas in a measuring gas space is provided. The sensor has a housing which includes a housing opening. At least one connection cable is led from the housing through the housing opening. The sensor further includes at least one sealing body, in particular a grommet, the sealing body at least partially enclosing the connection cable. The sealing body has at least one first section and at least one second section, the first section having a higher deformability than the second section.