diff --git a/Cargo.lock b/Cargo.lock
index ab3fbb7580c..8e32c3d0736 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -3702,6 +3702,7 @@ dependencies = [
  "cargo",
  "clap 4.2.1",
  "env_logger 0.10.0",
+ "log",
 ]
 
 [[package]]
diff --git a/crates/xtask/Cargo.toml b/crates/xtask/Cargo.toml
index 8af48c88cfa..ffe4cafbe37 100644
--- a/crates/xtask/Cargo.toml
+++ b/crates/xtask/Cargo.toml
@@ -6,6 +6,7 @@ publish = false
 
 [dependencies]
 anyhow = "1.0.47"
-cargo = { version = "0.71.0", path = "../.." }
+cargo = { path = "../.." }
 clap = "4.2.0"
 env_logger = "0.10.0"
+log = "0.4.17"
diff --git a/crates/xtask/src/main.rs b/crates/xtask/src/main.rs
index 1942a3621cf..9edb3c3d72a 100644
--- a/crates/xtask/src/main.rs
+++ b/crates/xtask/src/main.rs
@@ -1,3 +1,4 @@
+mod unpublished;
 mod xtask;
 
 fn main() {
diff --git a/crates/xtask/src/unpublished.rs b/crates/xtask/src/unpublished.rs
new file mode 100644
index 00000000000..7c1f44af41d
--- /dev/null
+++ b/crates/xtask/src/unpublished.rs
@@ -0,0 +1,86 @@
+use cargo::core::registry::PackageRegistry;
+use cargo::core::QueryKind;
+use cargo::core::Registry;
+use cargo::core::SourceId;
+use cargo::util::command_prelude::*;
+
+pub fn cli() -> clap::Command {
+    clap::Command::new("unpublished")
+}
+
+pub fn exec(args: &clap::ArgMatches, config: &mut cargo::util::Config) -> cargo::CliResult {
+    let ws = args.workspace(config)?;
+    let mut results = Vec::new();
+    {
+        let mut registry = PackageRegistry::new(config)?;
+        let _lock = config.acquire_package_cache_lock()?;
+        registry.lock_patches();
+        let source_id = SourceId::crates_io(config)?;
+
+        for member in ws.members() {
+            let name = member.name();
+            let current = member.version();
+            if member.publish() == &Some(vec![]) {
+                log::trace!("skipping {name}, `publish = false`");
+                continue;
+            }
+
+            let version_req = format!("<={current}");
+            let query = cargo::core::dependency::Dependency::parse(
+                name,
+                Some(&version_req),
+                source_id.clone(),
+            )?;
+            let possibilities = loop {
+                // Exact to avoid returning all for path/git
+                match registry.query_vec(&query, QueryKind::Exact) {
+                    std::task::Poll::Ready(res) => {
+                        break res?;
+                    }
+                    std::task::Poll::Pending => registry.block_until_ready()?,
+                }
+            };
+            if let Some(last) = possibilities.iter().map(|s| s.version()).max() {
+                if last != current {
+                    results.push((
+                        name.to_string(),
+                        Some(last.to_string()),
+                        current.to_string(),
+                    ));
+                } else {
+                    log::trace!("{name} {current} is published");
+                }
+            } else {
+                results.push((name.to_string(), None, current.to_string()));
+            }
+        }
+    }
+
+    if !results.is_empty() {
+        results.insert(
+            0,
+            (
+                "name".to_owned(),
+                Some("published".to_owned()),
+                "current".to_owned(),
+            ),
+        );
+        results.insert(
+            1,
+            (
+                "====".to_owned(),
+                Some("=========".to_owned()),
+                "=======".to_owned(),
+            ),
+        );
+    }
+    for (name, last, current) in results {
+        if let Some(last) = last {
+            println!("{name} {last} {current}");
+        } else {
+            println!("{name} - {current}");
+        }
+    }
+
+    Ok(())
+}
diff --git a/crates/xtask/src/xtask.rs b/crates/xtask/src/xtask.rs
index 00541358b17..1d6948fc7d7 100644
--- a/crates/xtask/src/xtask.rs
+++ b/crates/xtask/src/xtask.rs
@@ -2,6 +2,8 @@ use cargo::util::command_prelude::*;
 
 pub fn cli() -> clap::Command {
     clap::Command::new("xtask")
+        .subcommand_required(true)
+        .arg_required_else_help(true)
         .arg(
             opt(
                 "verbose",
@@ -29,11 +31,18 @@ pub fn cli() -> clap::Command {
                 .action(ArgAction::Append)
                 .global(true),
         )
+        .subcommands([crate::unpublished::cli()])
 }
 
 pub fn exec(args: &clap::ArgMatches, config: &mut cargo::util::Config) -> cargo::CliResult {
     config_configure(config, args)?;
 
+    match args.subcommand() {
+        Some(("unpublished", args)) => crate::unpublished::exec(args, config)?,
+        Some((name, _)) => unreachable!("clap enforces {name} to not exist"),
+        None => unreachable!("clap enforces a subcommand is present"),
+    }
+
     Ok(())
 }
 
@@ -67,3 +76,8 @@ fn config_configure(config: &mut Config, args: &ArgMatches) -> CliResult {
     )?;
     Ok(())
 }
+
+#[test]
+fn verify_cli() {
+    cli().debug_assert();
+}