diff --git a/CHANGES.md b/CHANGES.md
index c2aa7359080b..4a81a04627d8 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -1,3 +1,18 @@
+Synapse 1.10.0rc3 (2020-02-10)
+==============================
+
+Features
+--------
+
+- Filter out m.room.aliases from the CS API to mitigate abuse while a better solution is specced. ([\#6878](https://github.com/matrix-org/synapse/issues/6878))
+
+
+Internal Changes
+----------------
+
+- Fix continuous integration failures with old versions of `pip`, which were introduced by a release of the `zipp` library. ([\#6880](https://github.com/matrix-org/synapse/issues/6880))
+
+
 Synapse 1.10.0rc2 (2020-02-06)
 ==============================
 
diff --git a/changelog.d/6880.misc b/changelog.d/6880.misc
deleted file mode 100644
index 8344a6ed1eed..000000000000
--- a/changelog.d/6880.misc
+++ /dev/null
@@ -1 +0,0 @@
-Fix continuous integration failures with old versions of `pip`, which were introduced by a release of the `zipp` library.
diff --git a/synapse/__init__.py b/synapse/__init__.py
index 4f1859bd57bc..36c0cf557acc 100644
--- a/synapse/__init__.py
+++ b/synapse/__init__.py
@@ -36,7 +36,7 @@
 except ImportError:
     pass
 
-__version__ = "1.10.0rc2"
+__version__ = "1.10.0rc3"
 
 if bool(os.environ.get("SYNAPSE_TEST_PATCH_LOG_CONTEXTS", False)):
     # We import here so that we don't have to install a bunch of deps when
diff --git a/synapse/visibility.py b/synapse/visibility.py
index 100dc47a8a04..d0abd8f04ffc 100644
--- a/synapse/visibility.py
+++ b/synapse/visibility.py
@@ -122,6 +122,13 @@ def allowed(event):
         if not event.is_state() and event.sender in ignore_list:
             return None
 
+        # Until MSC2261 has landed we can't redact malicious alias events, so for
+        # now we temporarily filter out m.room.aliases entirely to mitigate
+        # abuse, while we spec a better solution to advertising aliases
+        # on rooms.
+        if event.type == EventTypes.Aliases:
+            return None
+
         # Don't try to apply the room's retention policy if the event is a state event, as
         # MSC1763 states that retention is only considered for non-state events.
         if apply_retention_policies and not event.is_state():