The json-jwt gem before 1.11.0 for Ruby lacks an element count during the splitting of a JWE string.
github.com/nov/json-jwt
github.com/nov/json-jwt/commit/ada16e772906efdd035e3df49cb2ae372f0f948a
github.com/nov/json-jwt/compare/v1.10.2...v1.11.0
github.com/rubysec/ruby-advisory-db/blob/master/gems/json-jwt/CVE-2019-18848.yml
lists.debian.org/debian-lts-announce/2020/10/msg00001.html
nvd.nist.gov/vuln/detail/CVE-2019-18848