diff --git a/CHANGELOG.md b/CHANGELOG.md
index 8522ce191..2028af2a2 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -276,6 +276,8 @@
     - **Dependencies:** Bump STACKIT SDK core module from `v0.24.1` to `v0.25.0`
   - [v0.22.2](services/resourcemanager/CHANGELOG.md#v0222)
     - **Dependencies:** Bump STACKIT SDK core module to `v0.26.0`
+  - [v0.23.0](services/resourcemanager/CHANGELOG.md#v0230)
+    - **Feature:** Added `_UNKNOWN_DEFAULT_OPEN_API` fallback value to all enums to handle unknown API values gracefully.
 - `runcommand`:
   - [v1.6.3](services/runcommand/CHANGELOG.md#v163) 
     - **Dependencies:** Bump STACKIT SDK core module from `v0.24.0` to `v0.24.1`
diff --git a/services/resourcemanager/CHANGELOG.md b/services/resourcemanager/CHANGELOG.md
index 41fa74e23..59f6bb77a 100644
--- a/services/resourcemanager/CHANGELOG.md
+++ b/services/resourcemanager/CHANGELOG.md
@@ -1,3 +1,6 @@
+## v0.23.0
+- **Feature:** Added `_UNKNOWN_DEFAULT_OPEN_API` fallback value to all enums to handle unknown API values gracefully.
+
 ## v0.22.2
 - **Dependencies:** Bump STACKIT SDK core module to `v0.26.0`
 
diff --git a/services/resourcemanager/VERSION b/services/resourcemanager/VERSION
index d13a21269..0c2a959e8 100644
--- a/services/resourcemanager/VERSION
+++ b/services/resourcemanager/VERSION
@@ -1 +1 @@
-v0.22.2
+v0.23.0
diff --git a/services/resourcemanager/oas_commit b/services/resourcemanager/oas_commit
index b95d3c889..6fdb25c73 100644
--- a/services/resourcemanager/oas_commit
+++ b/services/resourcemanager/oas_commit
@@ -1 +1 @@
-2f884c6bfba1c6294aa8ed17cda9b1704f935231
+c8e6adbf2c24050dca06a64b301b3a43ba28be6e
diff --git a/services/resourcemanager/v0api/model_lifecycle_state.go b/services/resourcemanager/v0api/model_lifecycle_state.go
index ac37a8838..5ee1148c0 100644
--- a/services/resourcemanager/v0api/model_lifecycle_state.go
+++ b/services/resourcemanager/v0api/model_lifecycle_state.go
@@ -20,10 +20,11 @@ type LifecycleState string
 
 // List of LifecycleState
 const (
-	LIFECYCLESTATE_CREATING LifecycleState = "CREATING"
-	LIFECYCLESTATE_ACTIVE   LifecycleState = "ACTIVE"
-	LIFECYCLESTATE_DELETING LifecycleState = "DELETING"
-	LIFECYCLESTATE_INACTIVE LifecycleState = "INACTIVE"
+	LIFECYCLESTATE_CREATING                 LifecycleState = "CREATING"
+	LIFECYCLESTATE_ACTIVE                   LifecycleState = "ACTIVE"
+	LIFECYCLESTATE_DELETING                 LifecycleState = "DELETING"
+	LIFECYCLESTATE_INACTIVE                 LifecycleState = "INACTIVE"
+	LIFECYCLESTATE_UNKNOWN_DEFAULT_OPEN_API LifecycleState = "unknown_default_open_api"
 )
 
 // All allowed values of LifecycleState enum
@@ -32,6 +33,7 @@ var AllowedLifecycleStateEnumValues = []LifecycleState{
 	"ACTIVE",
 	"DELETING",
 	"INACTIVE",
+	"unknown_default_open_api",
 }
 
 func (v *LifecycleState) UnmarshalJSON(src []byte) error {
@@ -48,7 +50,8 @@ func (v *LifecycleState) UnmarshalJSON(src []byte) error {
 		}
 	}
 
-	return fmt.Errorf("%+v is not a valid LifecycleState", value)
+	*v = LIFECYCLESTATE_UNKNOWN_DEFAULT_OPEN_API
+	return nil
 }
 
 // NewLifecycleStateFromValue returns a pointer to a valid LifecycleState