Add some HoF entries.

content/security-hall-of-fame/findings.toml

@@ -1,3 +1,21 @@
+[[findings]]
+date = "2023-03-04"
+reporter.name = "Sleroq"
+reporter.link = "https://github.com/sleroq"
+summary = """
+Discovered a DoS attack on Dendrite by sending a specially crafted event, making it spend a lot of CPU.
+"""
+project = "Dendrite"
+
+[[findings]]
+date = "2023-02-10"
+reporter.name = "Dirk Klimpel - BWI GmbH"
+reporter.link = "https://github.com/dklimpel"
+summary = """
+Discovered a deactivated user could still log in in certain situations.
+"""
+project = "Synapse"
+
 [[findings]]
 date = "2022-10-18"
 reporter.name = "aoxsin"
@@ -46,6 +64,15 @@ landscape mode. Fixed in [Element iOS 1.9.1](https://github.com/vector-im/elemen
 """
 project = "Element iOS"
 
+[[findings]]
+date = "2022-06-23"
+reporter.name = "Ethan Reynolds"
+reporter.link = "https://github.com/reynoldsme/"
+summary = """
+Discovered a way to crash the bridge by sending a message into a bridged voice room.
+"""
+project = "matrix-appservice-discord"
+
 [[findings]]
 date = "2022-06-06"
 reporter.name = "Val Lorentz"