Pluto is a superset of Lua 5.4 with a focus on general-purpose programming. Scripts passing user-controlled values to http.request header values are affected. An attacker could use this to send arbitrary requests, potentially leveraging authentication tokens provided in the same headers table.
https://github.com/PlutoLang/Pluto/security/advisories/GHSA-w8xp-pmx2-37w7