diff --git a/tx/textual/valuerenderer/bench_test.go b/tx/textual/valuerenderer/bench_test.go
index fd485fbd76..5ce072ef2e 100644
--- a/tx/textual/valuerenderer/bench_test.go
+++ b/tx/textual/valuerenderer/bench_test.go
@@ -9,15 +9,15 @@ import (
 )
 
 var intValues = []protoreflect.Value{
-	protoreflect.ValueOfString("10.00"),
-	protoreflect.ValueOfString("999.00"),
-	protoreflect.ValueOfString("999.9999"),
-	protoreflect.ValueOfString("99999999.9999"),
+	protoreflect.ValueOfString("1000"),
+	protoreflect.ValueOfString("99900"),
+	protoreflect.ValueOfString("9999999"),
+	protoreflect.ValueOfString("999999999999"),
 	protoreflect.ValueOfString("9999999999999999999"),
-	protoreflect.ValueOfString("1000000000000000000000000000000000000000000000000000000.00"),
-	protoreflect.ValueOfString("77777777777.777777777777777777777700"),
-	protoreflect.ValueOfString("-77777777777.777777777777777777777700"),
-	protoreflect.ValueOfString("777777777777777777777777.77777777700"),
+	protoreflect.ValueOfString("100000000000000000000000000000000000000000000000000000000"),
+	protoreflect.ValueOfString("77777777777777777777777777777777700"),
+	protoreflect.ValueOfString("-77777777777777777777777777777777700"),
+	protoreflect.ValueOfString("77777777777777777777777777777777700"),
 }
 
 func BenchmarkIntValueRendererFormat(b *testing.B) {
@@ -37,6 +37,35 @@ func BenchmarkIntValueRendererFormat(b *testing.B) {
 	}
 }
 
+var decimalValues = []protoreflect.Value{
+	protoreflect.ValueOfString("10.00"),
+	protoreflect.ValueOfString("999.00"),
+	protoreflect.ValueOfString("999.9999"),
+	protoreflect.ValueOfString("99999999.9999"),
+	protoreflect.ValueOfString("9999999999999999999"),
+	protoreflect.ValueOfString("1000000000000000000000000000000000000000000000000000000.00"),
+	protoreflect.ValueOfString("77777777777.777777777777777777777700"),
+	protoreflect.ValueOfString("-77777777777.777777777777777777777700"),
+	protoreflect.ValueOfString("777777777777777777777777.77777777700"),
+}
+
+func BenchmarkDecimalValueRendererFormat(b *testing.B) {
+	ctx := context.Background()
+	dvr := new(decValueRenderer)
+	buf := new(bytes.Buffer)
+	b.ResetTimer()
+	b.ReportAllocs()
+
+	for i := 0; i < b.N; i++ {
+		for _, value := range intValues {
+			if err := dvr.Format(ctx, value, buf); err != nil {
+				b.Fatal(err)
+			}
+		}
+		buf.Reset()
+	}
+}
+
 var byteValues = []protoreflect.Value{
 	protoreflect.ValueOfBytes(bytes.Repeat([]byte("abc"), 1<<20)),
 	protoreflect.ValueOfBytes([]byte("999.00")),
diff --git a/tx/textual/valuerenderer/dec.go b/tx/textual/valuerenderer/dec.go
index 5ea72e110d..6c26876613 100644
--- a/tx/textual/valuerenderer/dec.go
+++ b/tx/textual/valuerenderer/dec.go
@@ -34,15 +34,15 @@ func (vr decValueRenderer) Parse(_ context.Context, r io.Reader) (protoreflect.V
 // object).
 func formatDecimal(v string) (string, error) {
 	parts := strings.Split(v, ".")
+	if len(parts) > 2 {
+		return "", fmt.Errorf("invalid decimal: too many points in %s", v)
+	}
+
 	intPart, err := formatInteger(parts[0])
 	if err != nil {
 		return "", err
 	}
 
-	if len(parts) > 2 {
-		return "", fmt.Errorf("invalid decimal %s", v)
-	}
-
 	if len(parts) == 1 {
 		return intPart, nil
 	}
@@ -52,5 +52,11 @@ func formatDecimal(v string) (string, error) {
 		return intPart, nil
 	}
 
+	// Ensure that the decimal part has only digits.
+	// https://github.com/cosmos/cosmos-sdk/issues/12811
+	if !hasOnlyDigits(decPart) {
+		return "", fmt.Errorf("non-digits detected after decimal point in: %q", decPart)
+	}
+
 	return intPart + "." + decPart, nil
 }
diff --git a/tx/textual/valuerenderer/dec_test.go b/tx/textual/valuerenderer/dec_test.go
new file mode 100644
index 0000000000..187c6fd551
--- /dev/null
+++ b/tx/textual/valuerenderer/dec_test.go
@@ -0,0 +1,35 @@
+package valuerenderer
+
+import (
+	"strings"
+	"testing"
+)
+
+func TestFormatDecimalNonDigits(t *testing.T) {
+	badCases := []string{
+		"10.a",
+		"1a.10",
+		"p1a10.",
+		"0.10p",
+		"--10",
+		"12.😎😎",
+		"11111111111133333333333333333333333333333a",
+		"11111111111133333333333333333333333333333 192892",
+	}
+
+	for _, value := range badCases {
+		value := value
+		t.Run(value, func(t *testing.T) {
+			s, err := formatDecimal(value)
+			if err == nil {
+				t.Fatal("Expected an error")
+			}
+			if g, w := err.Error(), "non-digits"; !strings.Contains(g, w) {
+				t.Errorf("Error mismatch\nGot:  %q\nWant substring: %q", g, w)
+			}
+			if s != "" {
+				t.Fatalf("Got a non-empty string: %q", s)
+			}
+		})
+	}
+}
diff --git a/tx/textual/valuerenderer/int.go b/tx/textual/valuerenderer/int.go
index 476dbe2b4b..572f3b9b17 100644
--- a/tx/textual/valuerenderer/int.go
+++ b/tx/textual/valuerenderer/int.go
@@ -2,6 +2,7 @@ package valuerenderer
 
 import (
 	"context"
+	"fmt"
 	"io"
 	"strings"
 
@@ -26,6 +27,18 @@ func (vr intValueRenderer) Parse(_ context.Context, r io.Reader) (protoreflect.V
 	panic("implement me")
 }
 
+func hasOnlyDigits(s string) bool {
+	if s == "" {
+		return false
+	}
+	for _, r := range s {
+		if r < '0' || r > '9' {
+			return false
+		}
+	}
+	return true
+}
+
 // formatInteger formats an integer into a value-rendered string. This function
 // operates with string manipulation (instead of manipulating the int or sdk.Int
 // object).
@@ -37,7 +50,11 @@ func formatInteger(v string) (string, error) {
 	}
 	if len(v) > 1 {
 		v = strings.TrimLeft(v, "0")
+	}
 
+	// Ensure that the string contains only digits at this point.
+	if !hasOnlyDigits(v) {
+		return "", fmt.Errorf("expecting only digits 0-9, but got non-digits in %q", v)
 	}
 
 	startOffset := 3
diff --git a/tx/textual/valuerenderer/int_test.go b/tx/textual/valuerenderer/int_test.go
new file mode 100644
index 0000000000..4e30599faf
--- /dev/null
+++ b/tx/textual/valuerenderer/int_test.go
@@ -0,0 +1,35 @@
+package valuerenderer
+
+import (
+	"strings"
+	"testing"
+)
+
+func TestFormatIntegerNonDigits(t *testing.T) {
+	badCases := []string{
+		"a10",
+		"1a10",
+		"p1a10",
+		"10p",
+		"--10",
+		"😎😎",
+		"11111111111133333333333333333333333333333a",
+		"11111111111133333333333333333333333333333 192892",
+	}
+
+	for _, value := range badCases {
+		value := value
+		t.Run(value, func(t *testing.T) {
+			s, err := formatInteger(value)
+			if err == nil {
+				t.Fatal("Expected an error")
+			}
+			if g, w := err.Error(), "but got non-digits in"; !strings.Contains(g, w) {
+				t.Errorf("Error mismatch\nGot:  %q\nWant substring: %q", g, w)
+			}
+			if s != "" {
+				t.Fatalf("Got a non-empty string: %q", s)
+			}
+		})
+	}
+}