Pumpkin (plain) — Food safety facts
Safe to share · Cats · full breakdown on the linked food page
Safe and useful — plain canned pumpkin helps both constipation and mild diarrhoea. Not pumpkin pie filling (has sugar/spice).
Short answer
Yes, that's perfectly safe for cats. Plain canned pumpkin is a useful fiber source and can help with both constipation and mild diarrhea. Just make sure it's pure pumpkin, not pumpkin pie filling which contains sugar and spices. Offer it plain, watch for any unusual vomiting, and contact your own vet if you see any concerning signs.