diff --git a/CHANGELOG.next.asciidoc b/CHANGELOG.next.asciidoc
index e594df1b8a2..9b73c52df06 100644
--- a/CHANGELOG.next.asciidoc
+++ b/CHANGELOG.next.asciidoc
@@ -102,6 +102,7 @@ https://github.com/elastic/beats/compare/v8.8.1\...main[Check the HEAD diff]
 - Fix parsing of RFC 3164 process IDs in syslog processor. {issue}38947[38947] {pull}38982[38982]
 - Rename the field "apache2.module.error" to "apache.module.error" in Apache error visualization. {issue}39480[39480] {pull}39481[39481]
 - Validate config of the `replace` processor {pull}40047[40047]
+- Allow port number 0 in the community ID flowhash processor {pull}40259[40259]
 - Fix handling of escaped brackets in syslog structured data. {issue}40445[40445] {pull}40446[40446]
 - Update Go version to 1.22.6. {pull}40528[40528]
 
diff --git a/libbeat/processors/communityid/communityid.go b/libbeat/processors/communityid/communityid.go
index 9490b041428..e2db51935a0 100644
--- a/libbeat/processors/communityid/communityid.go
+++ b/libbeat/processors/communityid/communityid.go
@@ -153,7 +153,7 @@ func (p *processor) buildFlow(event *beat.Event) *flowhash.Flow {
 			return nil
 		}
 		sp, ok := tryToUint(v)
-		if !ok || sp < 1 || sp > 65535 {
+		if !ok || sp > 65535 {
 			return nil
 		}
 		flow.SourcePort = uint16(sp)
@@ -164,7 +164,7 @@ func (p *processor) buildFlow(event *beat.Event) *flowhash.Flow {
 			return nil
 		}
 		dp, ok := tryToUint(v)
-		if !ok || dp < 1 || dp > 65535 {
+		if !ok || dp > 65535 {
 			return nil
 		}
 		flow.DestinationPort = uint16(dp)
diff --git a/libbeat/processors/communityid/communityid_test.go b/libbeat/processors/communityid/communityid_test.go
index e84eb50bdae..608787b9265 100644
--- a/libbeat/processors/communityid/communityid_test.go
+++ b/libbeat/processors/communityid/communityid_test.go
@@ -67,12 +67,6 @@ func TestRun(t *testing.T) {
 		testProcessor(t, 0, e, nil)
 	})
 
-	t.Run("invalid source port", func(t *testing.T) {
-		e := evt()
-		e.Put("source.port", 0)
-		testProcessor(t, 0, e, nil)
-	})
-
 	t.Run("invalid source port1", func(t *testing.T) {
 		e := evt()
 		e.Put("source.port", 123456)
@@ -85,12 +79,6 @@ func TestRun(t *testing.T) {
 		testProcessor(t, 0, e, nil)
 	})
 
-	t.Run("invalid destination port", func(t *testing.T) {
-		e := evt()
-		e.Put("destination.port", 0)
-		testProcessor(t, 0, e, nil)
-	})
-
 	t.Run("invalid destination port1", func(t *testing.T) {
 		e := evt()
 		e.Put("destination.port", 123456)
@@ -142,6 +130,18 @@ func TestRun(t *testing.T) {
 		testProcessor(t, 0, e, "1:D3t8Q1aFA6Ev0A/AO4i9PnU3AeI=")
 	})
 
+	t.Run("valid source port 0", func(t *testing.T) {
+		e := evt()
+		e.Put("source.port", 0)
+		testProcessor(t, 0, e, "1:yrNkRN7VyfVz1Wh12tjRHhxERxM=")
+	})
+
+	t.Run("valid destination port 0", func(t *testing.T) {
+		e := evt()
+		e.Put("destination.port", 0)
+		testProcessor(t, 0, e, "1:YaVkVTbWUkgn0a2QrblLOEsia9g=")
+	})
+
 	t.Run("iana number", func(t *testing.T) {
 		e := evt()
 		e.Delete("network.transport")