diff --git a/src/rules/security.py b/src/rules/security.py
new file mode 100644
index 0000000..6c31ead
--- /dev/null
+++ b/src/rules/security.py
@@ -0,0 +1,289 @@
+"""Security vulnerability detection rules."""
+
+import re
+from pathlib import Path
+from typing import Optional
+import tree_sitter
+
+from src.analyzers.base import (
+    Analyzer,
+    Finding,
+    FindingCategory,
+    SeverityLevel,
+)
+
+
+class SQLInjectionAnalyzer(Analyzer):
+    """Detect SQL injection vulnerabilities."""
+
+    DANGEROUS_FUNCTIONS = {
+        "execute": "cursor.execute",
+        "executemany": "cursor.executemany",
+        "raw_query": "db.raw_query",
+        "query": "db.query",
+    }
+
+    SQL_KEYWORDS = {
+        "select", "insert", "update", "delete", "drop", "create", "alter",
+        "union", "and", "or", "where", "from", "table", "database",
+    }
+
+    def rule_id(self) -> str:
+        return "security.sql_injection"
+
+    def rule_name(self) -> str:
+        return "SQL Injection Detection"
+
+    def severity(self) -> SeverityLevel:
+        return SeverityLevel.CRITICAL
+
+    def category(self) -> FindingCategory:
+        return FindingCategory.SECURITY
+
+    def analyze(
+        self, source_code: str, file_path: Path, tree: tree_sitter.Tree
+    ) -> list[Finding]:
+        findings = []
+        calls = self._get_calls(tree.root_node)
+
+        for call in calls:
+            func_name = self._get_function_name(call)
+            if func_name in self.DANGEROUS_FUNCTIONS:
+                args = self._get_arguments(call)
+                for i, arg in enumerate(args):
+                    if self._is_dangerous_sql(arg, source_code):
+                        line = self._get_line_number(call, source_code)
+                        findings.append(
+                            Finding(
+                                rule_id=self.rule_id(),
+                                rule_name=self.rule_name(),
+                                severity=self.severity(),
+                                category=self.category(),
+                                message="Potential SQL injection detected",
+                                suggestion="Use parameterized queries instead of string formatting",
+                                file_path=file_path,
+                                line_number=line,
+                                column=self._get_column(call),
+                                node=call,
+                            )
+                        )
+        return findings
+
+    def _get_calls(self, node: tree_sitter.Node) -> list[tree_sitter.Node]:
+        calls = []
+        if hasattr(node, "type") and node.type == "call":
+            calls.append(node)
+        if hasattr(node, "children"):
+            for child in node.children:
+                calls.extend(self._get_calls(child))
+        return calls
+
+    def _get_function_name(self, call: tree_sitter.Node) -> str:
+        if hasattr(call, "children") and len(call.children) > 0:
+            func = call.children[0]
+            if hasattr(func, "text"):
+                return func.text.decode() if isinstance(func.text, bytes) else str(func.text)
+        return ""
+
+    def _get_arguments(self, call: tree_sitter.Node) -> list[str]:
+        args = []
+        if hasattr(call, "children"):
+            for child in call.children:
+                if hasattr(child, "text"):
+                    text = child.text
+                    args.append(text.decode() if isinstance(text, bytes) else str(text))
+        return args
+
+    def _is_dangerous_sql(self, arg: str, source_code: str) -> bool:
+        lower_arg = arg.lower()
+        has_concatenation = "+" in arg or "%" in arg or "f\"" in arg or "'" in arg
+        has_sql_keyword = any(kw in lower_arg for kw in self.SQL_KEYWORDS)
+        return has_concatenation and has_sql_keyword
+
+    def _get_line_number(self, node: tree_sitter.Node, source_code: str) -> int:
+        lines = source_code.split("\n")
+        start_byte = node.start_byte if hasattr(node, "start_byte") else 0
+        line = 1
+        pos = 0
+        for line_num, line_text in enumerate(lines, 1):
+            if pos + len(line_text) >= start_byte:
+                return line_num
+            pos += len(line_text) + 1
+        return 1
+
+    def _get_column(self, node: tree_sitter.Node) -> int:
+        return node.start_column if hasattr(node, "start_column") else 0
+
+
+class EvalUsageAnalyzer(Analyzer):
+    """Detect eval() and exec() usage."""
+
+    DANGEROUS_FUNCTIONS = {"eval", "exec", "execfile", "compile"}
+
+    def rule_id(self) -> str:
+        return "security.eval_usage"
+
+    def rule_name(self) -> str:
+        return "Eval/Exec Usage Detection"
+
+    def severity(self) -> SeverityLevel:
+        return SeverityLevel.CRITICAL
+
+    def category(self) -> FindingCategory:
+        return FindingCategory.SECURITY
+
+    def analyze(
+        self, source_code: str, file_path: Path, tree: tree_sitter.Tree
+    ) -> list[Finding]:
+        findings = []
+        calls = self._get_calls(tree.root_node)
+
+        for call in calls:
+            func_name = self._get_function_name(call)
+            if func_name in self.DANGEROUS_FUNCTIONS:
+                line = self._get_line_number(call, source_code)
+                findings.append(
+                    Finding(
+                        rule_id=self.rule_id(),
+                        rule_name=self.rule_name(),
+                        severity=self.severity(),
+                        category=self.category(),
+                        message=f"Dangerous {func_name}() call detected",
+                        suggestion="Avoid using eval/exec as they can execute arbitrary code",
+                        file_path=file_path,
+                        line_number=line,
+                        column=self._get_column(call),
+                        node=call,
+                    )
+                )
+        return findings
+
+    def _get_calls(self, node: tree_sitter.Node) -> list[tree_sitter.Node]:
+        calls = []
+        if hasattr(node, "type") and node.type == "call":
+            calls.append(node)
+        if hasattr(node, "children"):
+            for child in node.children:
+                calls.extend(self._get_calls(child))
+        return calls
+
+    def _get_function_name(self, call: tree_sitter.Node) -> str:
+        if hasattr(call, "children") and len(call.children) > 0:
+            func = call.children[0]
+            if hasattr(func, "text"):
+                text = func.text
+                return text.decode() if isinstance(text, bytes) else str(text)
+        return ""
+
+    def _get_line_number(self, node: tree_sitter.Node, source_code: str) -> int:
+        lines = source_code.split("\n")
+        start_byte = node.start_byte if hasattr(node, "start_byte") else 0
+        pos = 0
+        for line_num, line_text in enumerate(lines, 1):
+            if pos + len(line_text) >= start_byte:
+                return line_num
+            pos += len(line_text) + 1
+        return 1
+
+    def _get_column(self, node: tree_sitter.Node) -> int:
+        return node.start_column if hasattr(node, "start_column") else 0
+
+
+class PathTraversalAnalyzer(Analyzer):
+    """Detect path traversal vulnerabilities."""
+
+    DANGEROUS_PATTERNS = [
+        r"\.\./",
+        r"\.\.\\",
+        r"join\s*\(\s*[\"'].*\.\.[\"']",
+    ]
+
+    VULNERABLE_FUNCTIONS = {
+        "open": "open()",
+        "file": "file()",
+        "os.path.join": "os.path.join()",
+        "Path": "Path()",
+    }
+
+    def rule_id(self) -> str:
+        return "security.path_traversal"
+
+    def rule_name(self) -> str:
+        return "Path Traversal Detection"
+
+    def severity(self) -> SeverityLevel:
+        return SeverityLevel.HIGH
+
+    def category(self) -> FindingCategory:
+        return FindingCategory.SECURITY
+
+    def analyze(
+        self, source_code: str, file_path: Path, tree: tree_sitter.Tree
+    ) -> list[Finding]:
+        findings = []
+        calls = self._get_calls(tree.root_node)
+
+        for call in calls:
+            func_name = self._get_function_name(call)
+            if func_name in self.VULNERABLE_FUNCTIONS:
+                args = self._get_arguments(call)
+                for arg in args:
+                    if self._contains_path_traversal(arg):
+                        line = self._get_line_number(call, source_code)
+                        findings.append(
+                            Finding(
+                                rule_id=self.rule_id(),
+                                rule_name=self.rule_name(),
+                                severity=self.severity(),
+                                category=self.category(),
+                                message="Potential path traversal detected",
+                                suggestion="Validate and sanitize file paths, use os.path.abspath()",
+                                file_path=file_path,
+                                line_number=line,
+                                column=self._get_column(call),
+                                node=call,
+                            )
+                        )
+        return findings
+
+    def _get_calls(self, node: tree_sitter.Node) -> list[tree_sitter.Node]:
+        calls = []
+        if hasattr(node, "type") and node.type == "call":
+            calls.append(node)
+        if hasattr(node, "children"):
+            for child in node.children:
+                calls.extend(self._get_calls(child))
+        return calls
+
+    def _get_function_name(self, call: tree_sitter.Node) -> str:
+        if hasattr(call, "children") and len(call.children) > 0:
+            func = call.children[0]
+            if hasattr(func, "text"):
+                text = func.text
+                return text.decode() if isinstance(text, bytes) else str(text)
+        return ""
+
+    def _get_arguments(self, call: tree_sitter.Node) -> list[str]:
+        args = []
+        if hasattr(call, "children"):
+            for child in call.children:
+                if hasattr(child, "text"):
+                    text = child.text
+                    args.append(text.decode() if isinstance(text, bytes) else str(text))
+        return args
+
+    def _contains_path_traversal(self, arg: str) -> bool:
+        return any(re.search(pattern, arg) for pattern in self.DANGEROUS_PATTERNS)
+
+    def _get_line_number(self, node: tree_sitter.Node, source_code: str) -> int:
+        lines = source_code.split("\n")
+        start_byte = node.start_byte if hasattr(node, "start_byte") else 0
+        pos = 0
+        for line_num, line_text in enumerate(lines, 1):
+            if pos + len(line_text) >= start_byte:
+                return line_num
+            pos += len(line_text) + 1
+        return 1
+
+    def _get_column(self, node: tree_sitter.Node) -> int:
+        return node.start_column if hasattr(node, "start_column") else 0