diff --git a/CHANGELOG.next.asciidoc b/CHANGELOG.next.asciidoc
index 0c551133719..a3778a2ffd4 100644
--- a/CHANGELOG.next.asciidoc
+++ b/CHANGELOG.next.asciidoc
@@ -58,6 +58,7 @@ https://github.com/elastic/beats/compare/v7.0.0-alpha2...master[Check the HEAD d
 - Fix index names for indexing not always guaranteed to be lower case. {pull}16081[16081]
 - Add `ssl.ca_sha256` option to the supported TLS option, this allow to check that a specific certificate is used as part of the verified chain. {issue}15717[15717]
 - Fix loading processors from annotation hints. {pull}16348[16348]
+- Upgrade go-ucfg to latest v0.8.3. {pull}16450{16450}
 
 *Auditbeat*
 
@@ -73,6 +74,7 @@ https://github.com/elastic/beats/compare/v7.0.0-alpha2...master[Check the HEAD d
 - Prevent Elasticsearch from spewing log warnings about redundant wildcards when setting up ingest pipelines for the `elasticsearch` module. {issue}15840[15840] {pull}15900[15900]
 - Fix mapping error for cloudtrail additionalEventData field {pull}16088[16088]
 - Fix a connection error in httpjson input. {pull}16123[16123]
+- Fix merging of fileset inputs to replace paths and append processors. {pull}16450{16450}
 
 *Heartbeat*
 
diff --git a/NOTICE.txt b/NOTICE.txt
index cae8fed4047..801a192509d 100644
--- a/NOTICE.txt
+++ b/NOTICE.txt
@@ -1484,8 +1484,8 @@ Apache License 2.0
 
 --------------------------------------------------------------------
 Dependency: github.com/elastic/go-ucfg
-Version: v0.8.2
-Revision: ab69586e10820006b250d04c98cc3b848e227808
+Version: v0.8.3
+Revision: f3ae3b220df32cfcae011ec6bbf87a711e6bf06b
 License type (autodetected): Apache-2.0
 ./vendor/github.com/elastic/go-ucfg/LICENSE:
 --------------------------------------------------------------------
diff --git a/filebeat/fileset/fileset.go b/filebeat/fileset/fileset.go
index e1419ee5a93..eccd019fcb5 100644
--- a/filebeat/fileset/fileset.go
+++ b/filebeat/fileset/fileset.go
@@ -34,6 +34,8 @@ import (
 	"strings"
 	"text/template"
 
+	"github.com/elastic/go-ucfg"
+
 	errw "github.com/pkg/errors"
 	"gopkg.in/yaml.v2"
 
@@ -355,7 +357,7 @@ func (fs *Fileset) getInputConfig() (*common.Config, error) {
 		if err != nil {
 			return nil, fmt.Errorf("Error creating config from input overrides: %v", err)
 		}
-		cfg, err = common.MergeConfigs(cfg, overrides)
+		cfg, err = common.MergeConfigsWithOptions([]*common.Config{cfg, overrides}, ucfg.FieldReplaceValues("**.paths"), ucfg.FieldAppendValues("**.processors"))
 		if err != nil {
 			return nil, fmt.Errorf("Error applying config overrides: %v", err)
 		}
diff --git a/libbeat/common/config.go b/libbeat/common/config.go
index 2f779d996bb..448b2476156 100644
--- a/libbeat/common/config.go
+++ b/libbeat/common/config.go
@@ -116,6 +116,16 @@ func MergeConfigs(cfgs ...*Config) (*Config, error) {
 	return config, nil
 }
 
+func MergeConfigsWithOptions(cfgs []*Config, options ...ucfg.Option) (*Config, error) {
+	config := NewConfig()
+	for _, c := range cfgs {
+		if err := config.MergeWithOpts(c, options...); err != nil {
+			return nil, err
+		}
+	}
+	return config, nil
+}
+
 func NewConfigWithYAML(in []byte, source string) (*Config, error) {
 	opts := append(
 		[]ucfg.Option{
@@ -164,6 +174,14 @@ func (c *Config) Merge(from interface{}) error {
 	return c.access().Merge(from, configOpts...)
 }
 
+func (c *Config) MergeWithOpts(from interface{}, opts ...ucfg.Option) error {
+	o := configOpts
+	if opts != nil {
+		o = append(o, opts...)
+	}
+	return c.access().Merge(from, o...)
+}
+
 func (c *Config) Unpack(to interface{}) error {
 	return c.access().Unpack(to, configOpts...)
 }
diff --git a/vendor/github.com/elastic/go-ucfg/CHANGELOG.md b/vendor/github.com/elastic/go-ucfg/CHANGELOG.md
index 01a9ea1d295..f0326ac78ef 100644
--- a/vendor/github.com/elastic/go-ucfg/CHANGELOG.md
+++ b/vendor/github.com/elastic/go-ucfg/CHANGELOG.md
@@ -14,6 +14,11 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 
 ### Fixed
 
+## [0.8.3]
+
+### Added
+- Added ability to adjust merging behavior based on field names in configuration. Using `ucfg.FieldMergeValues`, `ucfg.FieldReplaceValues`, `ucfg.FieldAppendValues`, and `ucfg.FieldPrependValues`. #151
+
 ## [0.8.2]
 
 ### Fixed
@@ -263,7 +268,8 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 - Introduced CHANGELOG.md for documenting changes to ucfg.
 
 
-[Unreleased]: https://github.com/elastic/go-ucfg/compare/v0.8.2...HEAD
+[Unreleased]: https://github.com/elastic/go-ucfg/compare/v0.8.3...HEAD
+[0.8.3]: https://github.com/elastic/go-ucfg/compare/v0.8.2...v0.8.3
 [0.8.2]: https://github.com/elastic/go-ucfg/compare/v0.8.1...v0.8.2
 [0.8.1]: https://github.com/elastic/go-ucfg/compare/v0.8.0...v0.8.1
 [0.8.0]: https://github.com/elastic/go-ucfg/compare/v0.7.0...v0.8.0
diff --git a/vendor/github.com/elastic/go-ucfg/merge.go b/vendor/github.com/elastic/go-ucfg/merge.go
index fa2dd074566..ff07a97c8f7 100644
--- a/vendor/github.com/elastic/go-ucfg/merge.go
+++ b/vendor/github.com/elastic/go-ucfg/merge.go
@@ -115,6 +115,10 @@ func mergeConfigDict(opts *options, to, from *Config) Error {
 		}
 
 		old, _ := to.fields.get(k)
+		opts, err := fieldOptsOverride(opts, k, -1)
+		if err != nil {
+			return err
+		}
 		merged, err := mergeValues(opts, old, v)
 		if err != nil {
 			return err
@@ -128,7 +132,12 @@ func mergeConfigDict(opts *options, to, from *Config) Error {
 }
 
 func mergeConfigArr(opts *options, to, from *Config) Error {
-	switch opts.configValueHandling {
+	currHandling := opts.configValueHandling
+	opts, err := fieldOptsOverride(opts, "*", -1)
+	if err != nil {
+		return err
+	}
+	switch currHandling {
 	case cfgReplaceValue:
 		return mergeConfigReplaceArr(opts, to, from)
 
@@ -177,8 +186,13 @@ func mergeConfigMergeArr(opts *options, to, from *Config) Error {
 			field:  fmt.Sprintf("%v", i),
 		}
 
+		// possible for individual index to be replaced
+		idxOpts, err := fieldOptsOverride(opts, "", i)
+		if err != nil {
+			return err
+		}
 		old := to.fields.array()[i]
-		merged, err := mergeValues(opts, old, arr[i])
+		merged, err := mergeValues(idxOpts, old, arr[i])
 		if err != nil {
 			return err
 		}
@@ -515,3 +529,57 @@ func normalizeString(ctx context, opts *options, str string) (value, Error) {
 
 	return newSplice(ctx, opts.meta, varexp), nil
 }
+
+func fieldOptsOverride(opts *options, fieldName string, idx int) (*options, Error) {
+	if opts.fieldHandlingTree == nil {
+		return opts, nil
+	}
+	cfgHandling, child, ok := opts.fieldHandlingTree.fieldHandling(fieldName, idx)
+	child, err := includeWildcard(child, opts.fieldHandlingTree)
+	if err != nil {
+		return nil, err
+	}
+	if !ok {
+		// Only return a new `options` when arriving at new nested child. This
+		// combined with optimizations in `includeWildcard` will ensure that only
+		// a new opts will be created and returned when absolutely required.
+		if child != nil && opts.fieldHandlingTree != child {
+			newOpts := *opts
+			newOpts.fieldHandlingTree = child
+			opts = &newOpts
+		}
+		return opts, nil
+	}
+	// Only return a new `options` if absolutely required.
+	if opts.configValueHandling != cfgHandling || opts.fieldHandlingTree != child {
+		newOpts := *opts
+		newOpts.configValueHandling = cfgHandling
+		newOpts.fieldHandlingTree = child
+		opts = &newOpts
+	}
+	return opts, nil
+}
+
+func includeWildcard(child *fieldHandlingTree, parent *fieldHandlingTree) (*fieldHandlingTree, Error) {
+	if parent == nil {
+		return child, nil
+	}
+	wildcard, err := parent.wildcard()
+	if err != nil {
+		return child, nil
+	}
+	if child == nil && len(parent.fields.dict()) == 1 {
+		// parent is already config with just wildcard
+		return parent, nil
+	}
+	sub := newFieldHandlingTree()
+	if child != nil {
+		if err := sub.merge(child); err != nil {
+			return nil, err.(Error)
+		}
+	}
+	if err := sub.setWildcard(wildcard); err != nil {
+		return nil, err.(Error)
+	}
+	return sub, nil
+}
diff --git a/vendor/github.com/elastic/go-ucfg/opts.go b/vendor/github.com/elastic/go-ucfg/opts.go
index ba954242829..68c23e562c9 100644
--- a/vendor/github.com/elastic/go-ucfg/opts.go
+++ b/vendor/github.com/elastic/go-ucfg/opts.go
@@ -18,7 +18,9 @@
 package ucfg
 
 import (
+	"fmt"
 	"os"
+	"strings"
 
 	"github.com/elastic/go-ucfg/parse"
 )
@@ -38,6 +40,7 @@ type options struct {
 	noParse      bool
 
 	configValueHandling configHandling
+	fieldHandlingTree   *fieldHandlingTree
 
 	// temporary cache of parsed splice values for lifetime of call to
 	// Unpack/Pack/Get/...
@@ -48,6 +51,9 @@ type options struct {
 
 type valueCache map[string]spliceValue
 
+// specific API on top of Config to handle adjusting merging behavior per fields
+type fieldHandlingTree Config
+
 // id used to store intermediate parse results in current execution context.
 // As parsing results might differ between multiple calls due to:
 // splice being shared between multiple configurations, or environment
@@ -162,6 +168,57 @@ func makeOptValueHandling(h configHandling) Option {
 	}
 }
 
+var (
+	// FieldMergeValues option configures all merging and unpacking operations to use
+	// the default merging behavior for the specified field. This overrides the any struct
+	// tags during unpack for the field. Nested field names can be defined using dot
+	// notation.
+	FieldMergeValues = makeFieldOptValueHandling(cfgMergeValues)
+
+	// FieldReplaceValues option configures all merging and unpacking operations to
+	// replace old dictionaries and arrays while merging for the specified field. This
+	// overrides the any struct tags during unpack for the field. Nested field names
+	// can be defined using dot notation.
+	FieldReplaceValues = makeFieldOptValueHandling(cfgReplaceValue)
+
+	// FieldAppendValues option configures all merging and unpacking operations to
+	// merge dictionaries and append arrays to existing arrays while merging for the
+	// specified field. This overrides the any struct tags during unpack for the field.
+	// Nested field names can be defined using dot notation.
+	FieldAppendValues = makeFieldOptValueHandling(cfgArrAppend)
+
+	// FieldPrependValues option configures all merging and unpacking operations to
+	// merge dictionaries and prepend arrays to existing arrays while merging for the
+	// specified field. This overrides the any struct tags during unpack for the field.
+	// Nested field names can be defined using dot notation.
+	FieldPrependValues = makeFieldOptValueHandling(cfgArrPrepend)
+)
+
+func makeFieldOptValueHandling(h configHandling) func(...string) Option {
+	return func(fieldName ...string) Option {
+		if len(fieldName) == 0 {
+			return func(_ *options) {}
+		}
+
+		table := make(map[string]configHandling)
+		for _, name := range fieldName {
+			// field value config options are rendered into a Config; the '*' represents the handling method
+			// for everything nested under this field.
+			if !strings.HasSuffix(name, ".*") {
+				name = fmt.Sprintf("%s.*", name)
+			}
+			table[name] = h
+		}
+
+		return func(o *options) {
+			if o.fieldHandlingTree == nil {
+				o.fieldHandlingTree = newFieldHandlingTree()
+			}
+			o.fieldHandlingTree.merge(table, PathSep(o.pathSep))
+		}
+	}
+}
+
 // VarExp option enables support for variable expansion. Resolve and Env options will only be effective if  VarExp is set.
 var VarExp Option = doVarExp
 
@@ -200,3 +257,59 @@ func (cache valueCache) cachedValue(
 	}
 	return v, err
 }
+
+func newFieldHandlingTree() *fieldHandlingTree {
+	return (*fieldHandlingTree)(New())
+}
+
+func (t *fieldHandlingTree) merge(other interface{}, opts ...Option) error {
+	cfg := (*Config)(t)
+	return cfg.Merge(other, opts...)
+}
+
+func (t *fieldHandlingTree) child(fieldName string, idx int) (*fieldHandlingTree, error) {
+	cfg := (*Config)(t)
+	child, err := cfg.Child(fieldName, idx)
+	if err != nil {
+		return nil, err
+	}
+	return (*fieldHandlingTree)(child), nil
+}
+
+func (t *fieldHandlingTree) configHandling(fieldName string, idx int) (configHandling, error) {
+	cfg := (*Config)(t)
+	handling, err := cfg.Uint(fieldName, idx)
+	if err != nil {
+		return cfgDefaultHandling, err
+	}
+	return configHandling(handling), nil
+}
+
+func (t *fieldHandlingTree) wildcard() (*fieldHandlingTree, error) {
+	return t.child("**", -1)
+}
+
+func (t *fieldHandlingTree) setWildcard(wildcard *fieldHandlingTree) error {
+	cfg := (*Config)(t)
+	return cfg.SetChild("**", -1, (*Config)(wildcard))
+}
+
+func (t *fieldHandlingTree) fieldHandling(fieldName string, idx int) (configHandling, *fieldHandlingTree, bool) {
+	child, err := t.child(fieldName, idx)
+	if err == nil {
+		cfgHandling, err := child.configHandling("*", -1)
+		if err == nil {
+			return cfgHandling, child, true
+		}
+	}
+	// try wildcard match
+	wildcard, err := t.wildcard()
+	if err != nil {
+		return cfgDefaultHandling, child, false
+	}
+	cfgHandling, cfg, ok := wildcard.fieldHandling(fieldName, idx)
+	if ok {
+		return cfgHandling, cfg, ok
+	}
+	return cfgDefaultHandling, child, ok
+}
diff --git a/vendor/vendor.json b/vendor/vendor.json
index fdd29cff5ea..a729034172a 100644
--- a/vendor/vendor.json
+++ b/vendor/vendor.json
@@ -3280,76 +3280,76 @@
 			"versionExact": "v0.0.7"
 		},
 		{
-			"checksumSHA1": "VPcK6uPDligSrbdi1yVeGivPvno=",
+			"checksumSHA1": "6EwlkLbm/yUYgLddYEiQRZioMNM=",
 			"path": "github.com/elastic/go-ucfg",
-			"revision": "ab69586e10820006b250d04c98cc3b848e227808",
-			"revisionTime": "2020-02-07T21:56:35Z",
-			"version": "v0.8.2",
-			"versionExact": "v0.8.2"
+			"revision": "f3ae3b220df32cfcae011ec6bbf87a711e6bf06b",
+			"revisionTime": "2020-02-20T11:45:39Z",
+			"version": "v0.8.3",
+			"versionExact": "v0.8.3"
 		},
 		{
 			"checksumSHA1": "X+R/CD8SokJrmlxFTx2nSevRDhQ=",
 			"path": "github.com/elastic/go-ucfg/cfgutil",
-			"revision": "ab69586e10820006b250d04c98cc3b848e227808",
-			"revisionTime": "2020-02-07T21:56:35Z",
-			"version": "v0.8.2",
-			"versionExact": "v0.8.2"
+			"revision": "f3ae3b220df32cfcae011ec6bbf87a711e6bf06b",
+			"revisionTime": "2020-02-20T11:45:39Z",
+			"version": "v0.8.3",
+			"versionExact": "v0.8.3"
 		},
 		{
 			"checksumSHA1": "B58nBBiUIstpkXfr9yaYN9GzdLE=",
 			"path": "github.com/elastic/go-ucfg/diff",
-			"revision": "ab69586e10820006b250d04c98cc3b848e227808",
-			"revisionTime": "2020-02-07T21:56:35Z",
-			"version": "v0.8.2",
-			"versionExact": "v0.8.2"
+			"revision": "f3ae3b220df32cfcae011ec6bbf87a711e6bf06b",
+			"revisionTime": "2020-02-20T11:45:39Z",
+			"version": "v0.8.3",
+			"versionExact": "v0.8.3"
 		},
 		{
 			"checksumSHA1": "E6k6DWkpI+LOKDIFRqRmNH9GORc=",
 			"path": "github.com/elastic/go-ucfg/flag",
-			"revision": "ab69586e10820006b250d04c98cc3b848e227808",
-			"revisionTime": "2020-02-07T21:56:35Z",
-			"version": "v0.8.2",
-			"versionExact": "v0.8.2"
+			"revision": "f3ae3b220df32cfcae011ec6bbf87a711e6bf06b",
+			"revisionTime": "2020-02-20T11:45:39Z",
+			"version": "v0.8.3",
+			"versionExact": "v0.8.3"
 		},
 		{
 			"checksumSHA1": "NhiQQjYMs/ViCbmEq9tll2uCaYo=",
 			"path": "github.com/elastic/go-ucfg/hjson",
-			"revision": "ab69586e10820006b250d04c98cc3b848e227808",
-			"revisionTime": "2020-02-07T21:56:35Z",
-			"version": "v0.8.2",
-			"versionExact": "v0.8.2"
+			"revision": "f3ae3b220df32cfcae011ec6bbf87a711e6bf06b",
+			"revisionTime": "2020-02-20T11:45:39Z",
+			"version": "v0.8.3",
+			"versionExact": "v0.8.3"
 		},
 		{
 			"checksumSHA1": "esXpiQlEvTOUwsE0nNesso8albo=",
 			"path": "github.com/elastic/go-ucfg/internal/parse",
 			"revision": "0539807037ce820e147797f051ff32b05f4f9288",
 			"revisionTime": "2019-01-28T11:18:48Z",
-			"version": "v0.8.2",
-			"versionExact": "v0.8.2"
+			"version": "v0.8.3",
+			"versionExact": "v0.8.3"
 		},
 		{
 			"checksumSHA1": "cfMNsyQm0gZOV0hRJrBSdKDQSBo=",
 			"path": "github.com/elastic/go-ucfg/json",
-			"revision": "ab69586e10820006b250d04c98cc3b848e227808",
-			"revisionTime": "2020-02-07T21:56:35Z",
-			"version": "v0.8.2",
-			"versionExact": "v0.8.2"
+			"revision": "f3ae3b220df32cfcae011ec6bbf87a711e6bf06b",
+			"revisionTime": "2020-02-20T11:45:39Z",
+			"version": "v0.8.3",
+			"versionExact": "v0.8.3"
 		},
 		{
 			"checksumSHA1": "ZISq+zzSb0OLzvwLlf1ObdgnFmM=",
 			"path": "github.com/elastic/go-ucfg/parse",
-			"revision": "ab69586e10820006b250d04c98cc3b848e227808",
-			"revisionTime": "2020-02-07T21:56:35Z",
-			"version": "v0.8.2",
-			"versionExact": "v0.8.2"
+			"revision": "f3ae3b220df32cfcae011ec6bbf87a711e6bf06b",
+			"revisionTime": "2020-02-20T11:45:39Z",
+			"version": "v0.8.3",
+			"versionExact": "v0.8.3"
 		},
 		{
 			"checksumSHA1": "cnJVnptTvXNLzxVhd266k19/pQg=",
 			"path": "github.com/elastic/go-ucfg/yaml",
-			"revision": "ab69586e10820006b250d04c98cc3b848e227808",
-			"revisionTime": "2020-02-07T21:56:35Z",
-			"version": "v0.8.2",
-			"versionExact": "v0.8.2"
+			"revision": "f3ae3b220df32cfcae011ec6bbf87a711e6bf06b",
+			"revisionTime": "2020-02-20T11:45:39Z",
+			"version": "v0.8.3",
+			"versionExact": "v0.8.3"
 		},
 		{
 			"checksumSHA1": "iI1JCWsrAPpoKcEo/i6G3lRLIVs=",