A covert timing channel vulnerability exists in the Bouncy Castle BC-JAVA core library affecting the FrodoKEM algorithm during decryption. This flaw arises from non-constant time comparisons that may leak private keys. Versions from 1.71 up to but not including 1.80.2, 1.81 up to but not including 1.81.1, and 1.82 up to but not including 1.84 are affected. The vulnerability allows an unauthenticated remote attacker to send malformed ciphertexts and perform statistical timing analysis to potentially recover private keys. Fixed versions include 1.80.2, 1.81.1, and 1.84. The CVSS v3.1 score is 7.5 (high severity).