nginx before versions 1.15.6 and 1.14.1 has a vulnerability in the implementation of HTTP/2 that can allow for excessive memory consumption. This issue affects nginx compiled with the ngx_http_v2_module (not compiled by default) if the 'http2' option of the 'listen' directive is used in a configuration file.
Exploitability
AV:NAC:LPR:NUI:NScope
S:UImpact
C:NI:NA:H7.5/CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HResource Management