The RSA 1.5 algorithm implementation in the JOSE_JWE class in JWE.php in jose-php before 2.2.1 lacks the Random Filling protection mechanism, which makes it easier for remote attackers to obtain cleartext data via a Million Message Attack (MMA).
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2016-5430.json"