Advisories for Golang/Github.com/Matrix-Org/Gomatrixserverlib package

Gomatrixserverlib is vulnerable to server-side request forgery, serving content from a private network it can access, under certain conditions.

gomatrixserverlib is a Go library for matrix protocol federation. Dendrite is a Matrix homeserver written in Go, an alternative to Synapse. The power level parsing within gomatrixserverlib was failing to parse the "events_default" key of the m.room.power_levels event, defaulting the event default power level to zero in all cases. Power levels are the matrix terminology for user access level. In rooms where the "events_default" power level had been changed, this …