[ci skip] Fix #4091
diff --git a/user_guide_src/source/changelog.rst b/user_guide_src/source/changelog.rst
index 00d992a..54dcea8 100644
--- a/user_guide_src/source/changelog.rst
+++ b/user_guide_src/source/changelog.rst
@@ -23,6 +23,7 @@
- Fixed a bug (#4066) - :doc:`Cache Library <libraries/caching>` couldn't fallback to a backup driver if the primary one is Memcache(d) or Redis.
- Fixed a bug (#4073) - :doc:`Email Library <libraries/email>` method ``send()`` could return TRUE in case of an actual failure when an SMTP command fails.
- Fixed a bug (#4086) - :doc:`Query Builder <database/query_builder>` didn't apply *dbprefix* to LIKE conditions if the pattern included spaces.
+- Fixed a bug (#4091) - :doc:`Cache Library <libraries/caching>` 'file' driver could be tricked into accepting empty cache item IDs.
Version 3.0.1
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