Portuguese defender Ribeiro conjured up a precise finish to put the home side ahead within the first five minutes, while substitute Grabban made certain of victory in the 87th minute, as he made his first appearance since October, following a hip injury.
It left Owls boss Tony Pulis to notch up an eighth game without a win since taking on the job.
In contrast, Hughton will have been delighted to see his Forest side avoid notching up eight games without victory himself.
It took only four minutes for Forest to take the lead with a well-crafted goal.
Cafu delivered the final ball into the path of Ribeiro as he rampaged down the left flank and the full-back powered into the box before firing a low shot across goal and into the bottom corner.
Amid a packed goalmouth, keeper Joe Wildsmith had little chance of keeping the ball out.
Forest started the game brightly and, while they had a scare when Lyle Taylor needed extensive treatment to a knock, the striker was soon bending a powerful free-kick high and wide of the target.
Cafu had the ball in the net when he got on the end of a cross-shot from Sammy Ameobi but the Forest man had strayed offside.
Kadeem Harris ensured Forest keeper Brice Samba remained alert with a shot from the edge of the box, which was well held.
Forest were playing well and were only denied a second when Chey Dunkley cleared off the line to keep out an effort from Taylor, as he slid to connect with a cut back from Ribeiro.
A fine cross from Barry Bannan caused chaos at the other end but Adam Reach could not quite connect at the far post.
Ribeiro saw another shot deflected wide for a corner at the start of the second half. Another clever pass from Cafu sent Cyrus Christie into space, but his cross was behind Taylor in the middle.
Cafu was at the centre of things again as Ameobi exchanged passes with him, before driving a low 20-yard shot that was well held by Wildsmith.
Ameobi and Alex Mighten both had shots blocked, before Mighten sent a header over as the two men combined.
But sub Grabban made the difference when he challenged Tom Lees for the ball on the edge of the penalty area, before finding the corner with a precise finish to secure three points.