diff --git a/CHANGELOG.md b/CHANGELOG.md
index e1b2750..950fb70 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,13 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/), and this
 
 ## [Unreleased]
 
+## [5.9.2] - 2026-05-05
+
+### Fixed
+
+- **S3 multipart NPE on error responses** — `S3ResponseHandler` no longer throws `NullPointerException` when an MPU part PUT returns a non-2xx response without an `ETag` header. The handler previously attempted to record a null ETag into the parent task's context map (a `ConcurrentHashMap`, which rejects null values), surfacing as misleading "Premature channel closure" warnings that masked the real upstream 4xx/5xx failure. (PR #105)
+- **Item name corruption with versioning enabled** — when versioning was enabled and a response omitted the `x-amz-version-id` header, the literal string "null" was appended to the item name (compounding `~null~null~…` across retries). Both header reads now early-out cleanly when absent. (PR #105)
+
 ## [5.9.1] - 2026-05-01
 
 ### Added
diff --git a/VERSION b/VERSION
index 9266671..da90218 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-5.9.1
\ No newline at end of file
+5.9.2
diff --git a/engine/core/spt-base/src/main/resources/config/defaults.yaml b/engine/core/spt-base/src/main/resources/config/defaults.yaml
index 0c8d122..ba3766a 100644
--- a/engine/core/spt-base/src/main/resources/config/defaults.yaml
+++ b/engine/core/spt-base/src/main/resources/config/defaults.yaml
@@ -117,7 +117,7 @@ run:
   node: false
   port: 9999
   scenario: null
-  version: 5.9.1
+  version: 5.9.2
 
 log:
   level: info