diff --git a/src/lai_automation/security.py b/src/lai_automation/security.py
index 5fe005e..4a37245 100644
--- a/src/lai_automation/security.py
+++ b/src/lai_automation/security.py
@@ -35,6 +35,11 @@ _PROTECTED_REPOSITORY_PATH = re.compile(
 _PARENT_PATH = re.compile(r"(?:^|[/\s'\"=])\.\.(?:/|$|[\s'\";&|])")
 _BACKGROUND_PROCESS = re.compile(r"(?<![&>])&(?![&>])")
 _SERVER_COMMAND = re.compile(r"(?<![A-Za-z0-9_.-])php\s+-S(?:\s|$)")
+_TEMPORARY_ARTIFACT = re.compile(
+    r"(?i)(?:^|[/\s'\"=])(?:[^/\s'\";&|<>]+\.(?:bak|backup|orig|rej|swp|temp|tmp)"
+    r"|(?:test_)?debug\.(?:php|py|js|ts)|scratch\.(?:php|py|js|ts))"
+    r"(?=$|[\s'\";&|<>])"
+)
 _CHANGE_DIRECTORY = re.compile(
     r"(?:^|[;&|]\s*)cd\s+(?P<target>'[^']*'|\"[^\"]*\"|[^\s;&|]+)"
 )
@@ -158,6 +163,8 @@ class SafeLocalEnvironment:
             raise ValueError("Command rejected by safety policy: path outside repository")
         if _PROTECTED_REPOSITORY_PATH.search(command):
             raise ValueError("Command rejected by safety policy: protected repository path")
+        if _TEMPORARY_ARTIFACT.search(command):
+            raise ValueError("Command rejected by safety policy: temporary artifact")
         if _BACKGROUND_PROCESS.search(command) or _SERVER_COMMAND.search(command):
             raise ValueError("Command rejected by safety policy: persistent process")
         for match in _CHANGE_DIRECTORY.finditer(command):
diff --git a/tests/test_security.py b/tests/test_security.py
index ab888a5..d8dd860 100644
--- a/tests/test_security.py
+++ b/tests/test_security.py
@@ -48,6 +48,9 @@ def test_environment_rejects_cwd_outside_repository(tmp_path: Path) -> None:
         "cd .. && pwd",
         "php -S 127.0.0.1:8000",
         "php artisan serve &",
+        "cp config/app.php config/app.php.bak",
+        "printf debug > test_debug.php",
+        "touch scratch.py",
     ],
 )
 def test_environment_rejects_unsafe_commands(tmp_path: Path, command: str) -> None: