diff --git a/docs/CHANGELOG.md b/docs/CHANGELOG.md
index 1d5408e12..75289344f 100644
--- a/docs/CHANGELOG.md
+++ b/docs/CHANGELOG.md
@@ -32,6 +32,8 @@ See also [LTS releases](https://docs.victoriametrics.com/lts-releases/).
 
 **Update note 1: the `--vm-disable-progress-bar` command-line flag at `vmctl` was deprecated. Use `--disable-progress-bar` instead.**
 
+**Update note 2: `*.passwordFile` and similar flags are no longer trimming trailing whitespaces at the end of content. Make sure to update the templating of password files or HTTP endpoints to not include trailing whitespaces before the upgrade. See [this](https://github.com/VictoriaMetrics/VictoriaMetrics/pull/6503) PR for the details.**
+
 * FEATURE: all VictoriaMetrics components: use constant-time comparison for comparing HTTP basic auth credentials and auth keys. This should prevent timing attacks when comparing these credentials. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/6392) for details. Thanks to @wasim-nihal for [the pull request](https://github.com/VictoriaMetrics/VictoriaMetrics/pull/6423).
 * FEATURE: [alerts-vmagent](https://github.com/VictoriaMetrics/VictoriaMetrics/blob/master/deployment/docker/alerts-vmagent.yml): add new alerting rules `StreamAggrFlushTimeout` and `StreamAggrDedupFlushTimeout` to notify about issues during stream aggregation.
 * FEATURE: [dashboards/vmagent](https://grafana.com/grafana/dashboards/12683): add row `Streaming aggregation` with panels related to [streaming aggregation](https://docs.victoriametrics.com/stream-aggregation/) process.
@@ -43,6 +45,7 @@ See also [LTS releases](https://docs.victoriametrics.com/lts-releases/).
 * FEATURE: [vmalert-tool](https://docs.victoriametrics.com/vmalert-tool/): support file path with hierarchical patterns and regexpes, and http url in unittest cmd-line flag `-files`, e.g. `-files="http://<some-server-addr>/path/to/rules"` or `-files="dir/**/*.yaml"`.
 
 * BUGFIX: all VictoriaMetrics components: prioritize `-configAuthKey` and `-reloadAuthKey` over `-httpAuth.*` settings. This change aligns behavior of mentioned flags with other auth flags like `-metricsAuthKey`, `-flagsAuthKey`, `-pprofAuthKey`. Check [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/6329).
+* BUGFIX: all VictoriaMetrics components: do not trim trailing spaces when reading content from `*.passwordFile` and similar flags. Previously, trailing spaces were trimmed from the content of the password file, which could lead to unexpected authentication errors.
 * BUGFIX: [vmctl](https://docs.victoriametrics.com/vmctl/): add `--disable-progress-bar` global command-line flag. It can be used for disabling dynamic progress bar for all migration modes. `--vm-disable-progress-bar`  command-line flag is deprecated and will be removed in the future releases. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/6367).
 * BUGFIX: [stream aggregation](https://docs.victoriametrics.com/stream-aggregation/): prevent [rate_sum](https://docs.victoriametrics.com/stream-aggregation/#rate_sum) and [rate_avg](https://docs.victoriametrics.com/stream-aggregation/#rate_avg) producing `NaN` results for stale time series. Before, when series matched for aggregation became stale or weren't updated during aggregation interval, the `rate_sum` or `rate_avg` could produce data point with `NaN` value. During visualization, such aggregation results would be displayed as gaps in time series.
 * BUGFIX: [vmalert](https://docs.victoriametrics.com/vmalert/): fix path for system links printed on default vmalert's UI page when `-http.pathPrefix` is set.
diff --git a/lib/flagutil/password_test.go b/lib/flagutil/password_test.go
index 8a9583406..e7a03c2a1 100644
--- a/lib/flagutil/password_test.go
+++ b/lib/flagutil/password_test.go
@@ -32,7 +32,7 @@ func TestPassword(t *testing.T) {
 
 	// read the password from file by relative path
 	localPassFile := "testdata/password.txt"
-	expectedPassword = "foo-bar-baz"
+	expectedPassword = "foo-bar-baz\n\n\n"
 	path := "file://" + localPassFile
 	if err := p.Set(path); err != nil {
 		t.Fatalf("cannot set password to file: %s", err)
@@ -52,7 +52,7 @@ func TestPassword(t *testing.T) {
 	if err != nil {
 		t.Fatalf("unexpected error: %s", err)
 	}
-	expectedPassword = "foo-bar-baz"
+	expectedPassword = "foo-bar-baz\n\n\n"
 	path = "file://" + localPassFile
 	if err := p.Set(path); err != nil {
 		t.Fatalf("unexpected error: %s", err)
diff --git a/lib/fs/fscore/fscore.go b/lib/fs/fscore/fscore.go
index b67028203..03cc37562 100644
--- a/lib/fs/fscore/fscore.go
+++ b/lib/fs/fscore/fscore.go
@@ -7,8 +7,6 @@ import (
 	"net/url"
 	"os"
 	"path/filepath"
-	"strings"
-	"unicode"
 )
 
 // ReadPasswordFromFileOrHTTP reads password for the give path.
@@ -19,8 +17,7 @@ func ReadPasswordFromFileOrHTTP(path string) (string, error) {
 	if err != nil {
 		return "", err
 	}
-	pass := strings.TrimRightFunc(string(data), unicode.IsSpace)
-	return pass, nil
+	return string(data), nil
 }
 
 // ReadFileOrHTTP reads path either from local filesystem or from http if path starts with http or https.