Graphite before 1.3.15 has an integer underflow and resultant out-of-bounds write via Graphite actions, because slotat does not ensure that an offset is within the allowed slot-map range.Referenceshttps://github.com/silnrsi/graphite/commit/ad78c6b7319909e1540c1b134e115ced03417866https://github.com/silnrsi/graphite/compare/1.3.14...1.3.15
