diff --git a/SECURITY.md b/SECURITY.md
index 7f98faf..193a993 100644
--- a/SECURITY.md
+++ b/SECURITY.md
@@ -5,7 +5,7 @@
 If you discover a security vulnerability in nanobot, please report it by:
 
 1. **DO NOT** open a public GitHub issue
-2. Email the maintainers at [security@nanobot.ai] or create a private security advisory on GitHub
+2. Create a private security advisory on GitHub or contact the repository maintainers
 3. Include:
    - Description of the vulnerability
    - Steps to reproduce
diff --git a/nanobot/agent/tools/shell.py b/nanobot/agent/tools/shell.py
index 5d17448..5319c57 100644
--- a/nanobot/agent/tools/shell.py
+++ b/nanobot/agent/tools/shell.py
@@ -10,8 +10,7 @@ from nanobot.agent.tools.base import Tool
 
 # List of potentially dangerous command patterns
 DANGEROUS_PATTERNS = [
-    r'rm\s+-rf\s+/\s*$',  # rm -rf / (at root only)
-    r'rm\s+-rf\s+/(?![\w/])',  # rm -rf / followed by whitespace or end
+    r'rm\s+-rf\s+/(?:\s|$)',  # rm -rf / (at root, followed by space or end)
     r':\(\)\{\s*:\|:&\s*\};:',  # fork bomb
     r'mkfs\.',  # format filesystem
     r'dd\s+if=.*\s+of=/dev/(sd|hd)',  # overwrite disk
@@ -19,7 +18,7 @@ DANGEROUS_PATTERNS = [
 ]
 
 
-def _is_dangerous_command(command: str) -> tuple[bool, str | None]:
+def validate_command_safety(command: str) -> tuple[bool, str | None]:
     """
     Check if a command contains dangerous patterns.
     
@@ -66,7 +65,7 @@ class ExecTool(Tool):
     
     async def execute(self, command: str, working_dir: str | None = None, **kwargs: Any) -> str:
         # Check for dangerous command patterns
-        is_dangerous, warning = _is_dangerous_command(command)
+        is_dangerous, warning = validate_command_safety(command)
         if is_dangerous:
             return f"Error: Refusing to execute dangerous command. {warning}"