A flaw was found in the way nettle's RSA decryption functions handled specially crafted ciphertext. An attacker could use this flaw to provide a manipulated ciphertext leading to application crash and denial of service.
https://security.netapp.com/advisory/ntap-20211104-0006/
https://security.gentoo.org/glsa/202401-24
https://lists.debian.org/debian-lts-announce/2021/09/msg00008.html