I presume the crack ends at either end when a full laminate sheet starts. I'f the action and triggerguard are properly tightened it shouldn't be a problem for firing as most of the recoil will be distributed around the sides and through the magazine walls. Fixing it would be tricky as being full of cosmolean, no epoxy will be able to penetrate the wood, and using various chemicals to dissolve the cosmo might wind up also attacking the glue.
If i were fixing it, i would cut out a "V" groove along the crack to get down to fresh wood, and then load it up with acraglass. Cross pins might not be necessary here as it doesn't really take recoil in the horizontal area, and its not a structural part right there, top down might wind up splitting the sheets and causing them to break out given how thin they are. I've never actually pinned a laminate that close to an edge so i cannot say how well it would hold up. If I would pin that i would do it in an "X" pattern.
The crack does look parallel with the bottom of the lug, is there any forward and back play in the lug? The crack looks to be slightly pushed out compared to its mating piece which would indicate to me someone fired it loose (or overpressure) and compressed the wood, breaking the area behind the lug

 

Your recoil lug is setting back. Common with 98k's. Next will be the split at the wrist if you dont get it bedded correctly.

 

Just from the pictures, you still have some cosmo in the stock. Get your hands on a cheap heat gun. Just remember to take it slow and don't get to close to the wood, you will see the cosmo seep out of it. When I do this I can tell by the smell of the cosmo when it's time to lay off on the heat and wipe it down, hard to explain. I like to use shop towels from an auto parts store, they hold up better and soak up more than the average paper towel in my opinion. I use them on my cast iron too, so it works.

As far as the crack, bedding would definitely need to be done, but finding a way to brace that section is beyond my expertise when it comes to preserving the value of the stock. There's plenty of people on here that have great advice on what to do, just take your time and learn as much as you can.

 

I've repaired quite a few over the last 40 years with Acraglas, clear fiberglass resin or Git-Rot (for dry rot in wooden boats). I like the Git-Rot because it's thinner and penetrates by capillary action into deep narrow cracks, especially when urged with compressed air. It's almost water-clear and won't leave a glue line if correctly clamped. Forget Crazy Glue, Gorilla Glue, G-B Weld, etc. which are milky or opaque when dry. Drip the resin in one end of the crack and wait for it to emerge from the other; that way you'll know when it's coated throughout.

The real key to success is to work out the clamping well beforehand; Don't reach for the glue until you already know exactly how you intend to clamp the joint so it will close completely, mate exactly and not show afterward. An assortment of soft-jawed ratchet clamps by Irwin or others is really indispensable. Make clamp jaws like templates from soft pine if needed to squeeze irregular contours.

Get the joint clean. Especially at the surface (unless you want to see a black line). Use acetone repeatedly --outdoors-- to saturate and degrease the joint. It will dissolve and evaporate the grease. Heat guns just thin the grease and drive it deeper. Orient the stock so the acetone drips out without unnecessarily running over the exterior of the stock; it will remove the color and make more work later.

Be ready to mop up all the excess adhesive when it's squeezed out.

The stock shown appears to be cracked also up on the right sidewall above the recoil lug. To push everything back into place you'll have to remove the lug. Do this VERY carefully to avoid splitting out the circular mortise in the sides, especially if the lug is set back even slightly.

The nice thing about repairing laminated stocks is that they tend to camouflage the repairs. Sometimes you need a magnifying glass to find where the crack was.

M