diff --git a/CHANGES.md b/CHANGES.md
index 66de9c915f..e1680d134a 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -1,3 +1,12 @@
+# Synapse 1.139.0rc3 (2025-09-25)
+
+## Bugfixes
+
+- Fix a bug introduced in 1.139.0rc1 where `run_coroutine_in_background(...)` incorrectly handled logcontexts, resulting in partially broken logging. ([\#18964](https://github.com/element-hq/synapse/issues/18964))
+
+
+
+
 # Synapse 1.139.0rc2 (2025-09-23)
 
 ## Internal Changes
diff --git a/debian/changelog b/debian/changelog
index 36fffe4d58..41d173ce55 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -1,3 +1,9 @@
+matrix-synapse-py3 (1.139.0~rc3) stable; urgency=medium
+
+  * New Synapse release 1.139.0rc3.
+
+ -- Synapse Packaging team <packages@matrix.org>  Thu, 25 Sep 2025 12:13:23 +0100
+
 matrix-synapse-py3 (1.139.0~rc2) stable; urgency=medium
 
   * New Synapse release 1.139.0rc2.
diff --git a/pyproject.toml b/pyproject.toml
index c548a652e9..7f58386087 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -101,7 +101,7 @@ module-name = "synapse.synapse_rust"
 
 [tool.poetry]
 name = "matrix-synapse"
-version = "1.138.2"
+version = "1.139.0rc3"
 description = "Homeserver for the Matrix decentralised comms protocol"
 authors = ["Matrix.org Team and Contributors <packages@matrix.org>"]
 license = "AGPL-3.0-or-later"