LDAP Injection Pattern Regex for Python

What this pattern does

This page provides a comprehensive, battle-tested regular expression for matching ldap injection pattern, ported and verified for Python. In security-sensitive code, using an unverified regex can open the door to both false positives and denial-of-service attacks. The snippet below is ready to drop into your Python project — whether you're validating in a Django view, a FastAPI endpoint, or a standalone data processing script.

Python Implementation

# LDAP Injection Pattern
# ReDoS-safe | RegexVault — Security > Injection Patterns

import re

ldap_injection_pattern_pattern = re.compile(r'[)(|*\\\x00]|(?:objectclass|objectCategory|objectGUID|samAccountName|userPrincipalName|memberOf)\s*=|(?:\(uid=)|(?:cn=)(?:[^,)]*\*)')

def validate_ldap_injection_pattern(value: str) -> bool:
    return bool(ldap_injection_pattern_pattern.fullmatch(value))

# Example
print(validate_ldap_injection_pattern("*)(uid=*))(|(uid=*"))  # True

Test Cases

When to use this pattern

This pattern is drawn from the Security > Injection Patterns category and carries a ReDoS-safe certification. That matters for Python developers because particularly important in Python web servers where CPU-bound regex operations can stall concurrent request handling. RegexVault audits patterns against known backtracking attack vectors, ensuring you have the necessary context before using this regex in a high-stakes production environment.

Common Pitfalls

Technical Notes

LDAP special characters: ( ) * \ and null byte. Classic injection: *(|(mail=*)) returns all records when injected into a filter. Defense: use LDAP parameter encoding to escape special characters in search filters. RFC 4515 defines the escape sequences.