ISO 27001 Control Reference Regex for Python

What this pattern does

This page provides a well-structured, multi-part regular expression for matching iso 27001 control reference, 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

# ISO 27001 Control Reference
# ReDoS-safe | RegexVault — Security > Audit & Compliance

import re

iso_27001_control_reference_pattern = re.compile(r'^(?:5|6|7|8)\.(?:[1-9]|[1-3][0-9]|4[0-1])(?:\.(?:[1-9]|[1-2][0-9]|30))?$')

def validate_iso_27001_control_reference(value: str) -> bool:
    return bool(iso_27001_control_reference_pattern.fullmatch(value))

# Example
print(validate_iso_27001_control_reference("5.1"))  # True

Test Cases

When to use this pattern

This pattern is drawn from the Security > Audit & Compliance 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

ISO 27001:2022 control domains: 5 (Organizational, controls 5.1-5.37), 6 (People, 6.1-6.8), 7 (Physical, 7.1-7.14), 8 (Technological, 8.1-8.34). The 2022 update reorganized from the 2013 version's A.5-A.18 structure. Clause 4-10 are the ISMS requirements (not controls).