PaperMC/paper-server/nms-patches/net/minecraft/world/level/block/SculkVeinBlock.patch

--- a/net/minecraft/world/level/block/SculkVeinBlock.java
+++ b/net/minecraft/world/level/block/SculkVeinBlock.java
@@ -121,7 +121,11 @@
                 if (iblockdata1.is(tagkey)) {
                     IBlockData iblockdata2 = Blocks.SCULK.defaultBlockState();
 
-                    generatoraccess.setBlock(blockposition1, iblockdata2, 3);
+                    // CraftBukkit start - Call BlockSpreadEvent
+                    if (!org.bukkit.craftbukkit.event.CraftEventFactory.handleBlockSpreadEvent(generatoraccess, blockposition, blockposition1, iblockdata2, 3)) {
+                        return false;
+                    }
+                    // CraftBukkit end
                     Block.pushEntitiesUp(iblockdata1, iblockdata2, generatoraccess, blockposition1);
                     generatoraccess.playSound((EntityHuman) null, blockposition1, SoundEffects.SCULK_BLOCK_SPREAD, SoundCategory.BLOCKS, 1.0F, 1.0F);
                     this.veinSpreader.spreadAll(iblockdata2, generatoraccess, blockposition1, sculkspreader.isWorldGeneration());