Haraka is a Node.js mail server. Prior to version 3.1.4, sending an email with proto: as a header name crashes the Haraka worker process. This issue has been patched in version 3.1.4.
Exploitability
AV:NAC:LAT:NPR:NUI:NVulnerable System
VC:NVI:NVA:HSubsequent System
SC:NSI:NSA:N8.7/CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:NOther