jats:titleAjats:scbstract</jats:sc> </jats:title> jats:pWe obtain finite-temperature M2 black branes in 11-dimensional supergravity, in a jats:italicG</jats:italic> jats:sub4</jats:sub>-flux background whose self-dual part approaches a solution of Cvetič, Gibbons, Lü, and Pope, based upon Stenzel’s family of Ricci-flat Kähler deformed cones. Our solutions are asymptotically jats:italicAdS</jats:italic> jats:sub4</jats:sub> times a 7-dimensional Stiefel manifold jats:italicV</jats:italic> jats:sub5,2</jats:sub>, and the branes are "smeared" to retain SO(5) symmetry in the internal space. The solutions represent a mass deformation of the corresponding dual jats:italicCFT</jats:italic> jats:sub3</jats:sub>, whose full description is at this time only partially-understood. We investigate the possibility of a confinement/de-confinement phase transition analogous to the jats:italicAdS</jats:italic> jats:sub5</jats:sub> × jats:italicS</jats:italic> jats:sup5</jats:sup> case, and a possible Gregory-Laflamme type instability which could lead to polarised brane solutions which break SO(5). We discuss possible consequences for AdS/CFT and the KKLT cosmological uplift mechanism.</jats:p>