In Nimbus JOSE+JWT before 4.39, there is no integer-overflow check when converting length values from bytes to bits, which allows attackers to conduct HMAC bypass attacks by shifting Additional Authenticated Data (AAD) and ciphertext so that different plaintext is obtained for the same HMAC.
bitbucket.org/connect2id/nimbus-jose-jwt/commits/0d2bd649ea386539220d4facfe1f65eb1dadb86c
bitbucket.org/connect2id/nimbus-jose-jwt/issues/224/byte-to-bit-overflow-in-cbc
bitbucket.org/connect2id/nimbus-jose-jwt/src/master/CHANGELOG.txt
lists.apache.org/thread.html/9317fd092b257a0815434b116a8af8daea6e920b6673f4fd5583d5fe@%3Ccommits.druid.apache.org%3E
nvd.nist.gov/vuln/detail/CVE-2017-12972