diff --git a/CLI/cmux.swift b/CLI/cmux.swift
index b14dad7c..c1c98599 100644
--- a/CLI/cmux.swift
+++ b/CLI/cmux.swift
@@ -4988,39 +4988,63 @@ struct CMUXCLI {
 
     private func versionSummary() -> String {
         let info = resolvedVersionInfo()
+        let commit = info["CMUXCommit"].flatMap { normalizedCommitHash($0) }
+        let baseSummary: String
         if let version = info["CFBundleShortVersionString"], let build = info["CFBundleVersion"] {
-            return "cmux \(version) (\(build))"
+            baseSummary = "cmux \(version) (\(build))"
+        } else if let version = info["CFBundleShortVersionString"] {
+            baseSummary = "cmux \(version)"
+        } else if let build = info["CFBundleVersion"] {
+            baseSummary = "cmux build \(build)"
+        } else {
+            baseSummary = "cmux version unknown"
         }
-        if let version = info["CFBundleShortVersionString"] {
-            return "cmux \(version)"
-        }
-        if let build = info["CFBundleVersion"] {
-            return "cmux build \(build)"
-        }
-        return "cmux version unknown"
+        guard let commit else { return baseSummary }
+        return "\(baseSummary) [\(commit)]"
     }
 
     private func resolvedVersionInfo() -> [String: String] {
+        var info: [String: String] = [:]
         if let main = versionInfo(from: Bundle.main.infoDictionary) {
-            return main
+            info.merge(main, uniquingKeysWith: { current, _ in current })
         }
 
-        for plistURL in candidateInfoPlistURLs() {
-            guard let data = try? Data(contentsOf: plistURL),
-                  let raw = try? PropertyListSerialization.propertyList(from: data, options: [], format: nil),
-                  let dictionary = raw as? [String: Any],
-                  let parsed = versionInfo(from: dictionary)
-            else {
-                continue
+        let needsPlistFallback =
+            info["CFBundleShortVersionString"] == nil ||
+            info["CFBundleVersion"] == nil ||
+            info["CMUXCommit"] == nil
+        if needsPlistFallback {
+            for plistURL in candidateInfoPlistURLs() {
+                guard let data = try? Data(contentsOf: plistURL),
+                      let raw = try? PropertyListSerialization.propertyList(from: data, options: [], format: nil),
+                      let dictionary = raw as? [String: Any],
+                      let parsed = versionInfo(from: dictionary)
+                else {
+                    continue
+                }
+                info.merge(parsed, uniquingKeysWith: { current, _ in current })
+                if info["CFBundleShortVersionString"] != nil,
+                   info["CFBundleVersion"] != nil,
+                   info["CMUXCommit"] != nil {
+                    break
+                }
             }
-            return parsed
         }
 
-        if let fromProject = versionInfoFromProjectFile() {
-            return fromProject
+        let needsProjectFallback =
+            info["CFBundleShortVersionString"] == nil ||
+            info["CFBundleVersion"] == nil ||
+            info["CMUXCommit"] == nil
+        if needsProjectFallback, let fromProject = versionInfoFromProjectFile() {
+            info.merge(fromProject, uniquingKeysWith: { current, _ in current })
         }
 
-        return [:]
+        if info["CMUXCommit"] == nil,
+           let commit = normalizedCommitHash(ProcessInfo.processInfo.environment["CMUX_COMMIT"]) {
+            info["CMUXCommit"] = commit
+        }
+
+        return info
     }
 
     private func versionInfo(from dictionary: [String: Any]?) -> [String: String]? {
@@ -5039,6 +5063,10 @@ struct CMUXCLI {
                 info["CFBundleVersion"] = trimmed
             }
         }
+        if let commit = dictionary["CMUXCommit"] as? String,
+           let normalizedCommit = normalizedCommitHash(commit) {
+            info["CMUXCommit"] = normalizedCommit
+        }
         return info.isEmpty ? nil : info
     }
 
@@ -5064,6 +5092,9 @@ struct CMUXCLI {
                 if let build = firstProjectSetting("CURRENT_PROJECT_VERSION", in: contents) {
                     info["CFBundleVersion"] = build
                 }
+                if let commit = gitCommitHash(at: current) {
+                    info["CMUXCommit"] = commit
+                }
                 if !info.isEmpty {
                     return info
                 }
@@ -5100,6 +5131,45 @@ struct CMUXCLI {
         return value
     }
 
+    private func gitCommitHash(at directory: URL) -> String? {
+        let process = Process()
+        let stdout = Pipe()
+        process.executableURL = URL(fileURLWithPath: "/usr/bin/env")
+        process.arguments = ["git", "-C", directory.path, "rev-parse", "--short=9", "HEAD"]
+        process.standardOutput = stdout
+        process.standardError = Pipe()
+
+        do {
+            try process.run()
+        } catch {
+            return nil
+        }
+        process.waitUntilExit()
+        guard process.terminationStatus == 0 else {
+            return nil
+        }
+
+        let data = stdout.fileHandleForReading.readDataToEndOfFile()
+        guard let output = String(data: data, encoding: .utf8) else {
+            return nil
+        }
+        return normalizedCommitHash(output)
+    }
+
+    private func normalizedCommitHash(_ value: String?) -> String? {
+        guard let value else { return nil }
+        let trimmed = value.trimmingCharacters(in: .whitespacesAndNewlines)
+        guard !trimmed.isEmpty, !trimmed.contains("$(") else {
+            return nil
+        }
+        let normalized = trimmed.lowercased()
+        let allowed = CharacterSet(charactersIn: "0123456789abcdef")
+        guard normalized.unicodeScalars.allSatisfy({ allowed.contains($0) }) else {
+            return nil
+        }
+        return String(normalized.prefix(12))
+    }
+
     private func candidateInfoPlistURLs() -> [URL] {
         guard let executable = currentExecutablePath(), !executable.isEmpty else {
             return []
diff --git a/tests/test_cli_version_commit_metadata.py b/tests/test_cli_version_commit_metadata.py
new file mode 100644
index 00000000..3029fe0d
--- /dev/null
+++ b/tests/test_cli_version_commit_metadata.py
@@ -0,0 +1,85 @@
+#!/usr/bin/env python3
+"""Regression test: CLI version output wiring keeps commit metadata support."""
+
+from __future__ import annotations
+
+import subprocess
+from pathlib import Path
+
+
+def get_repo_root() -> Path:
+    result = subprocess.run(
+        ["git", "rev-parse", "--show-toplevel"],
+        capture_output=True,
+        text=True,
+        check=False,
+    )
+    if result.returncode == 0:
+        return Path(result.stdout.strip())
+    return Path.cwd()
+
+
+def require(content: str, needle: str, message: str, failures: list[str]) -> None:
+    if needle not in content:
+        failures.append(message)
+
+
+def main() -> int:
+    repo_root = get_repo_root()
+    cli_path = repo_root / "CLI" / "cmux.swift"
+    if not cli_path.exists():
+        print(f"FAIL: missing expected file: {cli_path}")
+        return 1
+
+    content = cli_path.read_text(encoding="utf-8")
+    failures: list[str] = []
+
+    require(
+        content,
+        'let commit = info["CMUXCommit"].flatMap { normalizedCommitHash($0) }',
+        "versionSummary no longer reads CMUXCommit metadata",
+        failures,
+    )
+    require(
+        content,
+        'return "\\(baseSummary) [\\(commit)]"',
+        "versionSummary no longer appends commit metadata",
+        failures,
+    )
+    require(
+        content,
+        'if let commit = dictionary["CMUXCommit"] as? String,',
+        "Info.plist parsing no longer reads CMUXCommit",
+        failures,
+    )
+    require(
+        content,
+        "if let commit = gitCommitHash(at: current) {",
+        "Project fallback no longer probes git commit hash",
+        failures,
+    )
+    require(
+        content,
+        '["git", "-C", directory.path, "rev-parse", "--short=9", "HEAD"]',
+        "Git commit probe command changed unexpectedly",
+        failures,
+    )
+    require(
+        content,
+        'normalizedCommitHash(ProcessInfo.processInfo.environment["CMUX_COMMIT"])',
+        "Environment commit fallback (CMUX_COMMIT) is missing",
+        failures,
+    )
+
+    if failures:
+        print("FAIL: CLI version commit metadata regression(s) detected")
+        for failure in failures:
+            print(f"- {failure}")
+        return 1
+
+    print("PASS: CLI version commit metadata wiring is intact")
+    return 0
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())