diff --git a/db/migrate/20251001133644_add_detected_at_to_vulnerability_occurrences.rb b/db/migrate/20251001133644_add_detected_at_to_vulnerability_occurrences.rb
new file mode 100644
index 0000000000000000000000000000000000000000..5709bde047ff6f62ac657f23ff78b14274d709fa
--- /dev/null
+++ b/db/migrate/20251001133644_add_detected_at_to_vulnerability_occurrences.rb
@@ -0,0 +1,21 @@
+# frozen_string_literal: true
+
+class AddDetectedAtToVulnerabilityOccurrences < Gitlab::Database::Migration[2.3]
+  milestone '18.6'
+
+  disable_ddl_transaction!
+
+  def up
+    # rubocop:disable Migration/PreventAddingColumns -- The oversized nature of this table will be addressed through planned partitioning
+    with_lock_retries do
+      add_column :vulnerability_occurrences, :detected_at, :timestamptz, if_not_exists: true
+    end
+    # rubocop:enable Migration/PreventAddingColumns
+  end
+
+  def down
+    with_lock_retries do
+      remove_column :vulnerability_occurrences, :detected_at, if_exists: true
+    end
+  end
+end
diff --git a/db/schema_migrations/20251001133644 b/db/schema_migrations/20251001133644
new file mode 100644
index 0000000000000000000000000000000000000000..1219ce578b07b08b16d4ddeb982a317f9136d515
--- /dev/null
+++ b/db/schema_migrations/20251001133644
@@ -0,0 +1 @@
+55004e8a0c4820c7fb30966331ea2af35c900e150421d67dfbd04641ce63bcf7
\ No newline at end of file
diff --git a/db/structure.sql b/db/structure.sql
index 022d5f53aef66899b67b930e5e126f81745e0b74..055b26038ea39ac733e41bf245a5d1c5bbea8f3c 100644
--- a/db/structure.sql
+++ b/db/structure.sql
@@ -28394,6 +28394,7 @@ CREATE TABLE vulnerability_occurrences (
     initial_pipeline_id bigint,
     latest_pipeline_id bigint,
     security_project_tracked_context_id bigint,
+    detected_at timestamp with time zone,
     CONSTRAINT check_4a3a60f2ba CHECK ((char_length(solution) <= 7000)),
     CONSTRAINT check_ade261da6b CHECK ((char_length(description) <= 15000)),
     CONSTRAINT check_f602da68dd CHECK ((char_length(cve) <= 48400))