When the exponent is bigger than r, the group order of the pairing target group GT, the exponentiation à la GLV (ExpGLV) can sometimes give incorrect results compared to normal exponentiation (Exp). The issue impacts all users using ExpGLV for exponentiations in GT. This does not impact Exp and ExpCyclotomic which are sound. Also note that GLV methods in G1 and G2 are sound and not impacted. The issue is fixed in 0.12.1.