[ci skip] Prepare 3.1.9 release
diff --git a/user_guide_src/source/changelog.rst b/user_guide_src/source/changelog.rst
index 007e01c..5124809 100644
--- a/user_guide_src/source/changelog.rst
+++ b/user_guide_src/source/changelog.rst
@@ -5,11 +5,12 @@
Version 3.1.9
=============
-Release Date: Not Released
+Release Date: Jun 12, 2018
- **Security**
- Updated :doc:`URL Helper <helpers/url_helper>` function :php:func:`auto_link()` to add ``rel="noopener"`` to generated links in order to prevent tab hijacking.
+ - Fixed a possible session fixation vulnerability where the :doc:`Session Library <libraries/sessions>` enabled ``session.use_strict_mode`` but it didn't actually do anything (thanks to Aamer Shah, Prasanna Kumar).
- General Changes