Understanding Incident Response: What Is Annex A 5.26?
Information security incidents can happen to any business, but a structured, well-practised response is what separates resilient organisations from vulnerable ones. This is the core focus of ISO 27001 Annex A 5.26 Response to information security incidents. Its purpose is to ensure that when an incident occurs, you can mount an efficient and effective response to minimise potential damage and disruption.
The control itself is straightforward: information security incidents should be responded to in accordance with documented procedures. But what qualifies as an incident? An information security incident includes any event that compromises the confidentiality, integrity, or availability of information. This could be a data breach, a malware attack, or even the loss of a device containing sensitive data.
The primary objectives of an effective incident response process include:
- Containment and Mitigation: Limiting the spread and impact of incidents to prevent them from escalating.
- Recovery and Restoration: Ensuring the swift restoration of normal operations and services to get your business back on track.
- Learning and Improving: Identifying the root cause of vulnerabilities and using those lessons to implement preventive measures, strengthening your overall security posture.
For companies operating in the artificial intelligence sector, applying this control requires a deeper understanding of the unique risks you face.
Table of contents
The Unique Challenge for AI Companies
For your AI company, an information security incident poses unique threats that go beyond traditional IT systems. Your most valuable assets, including proprietary models, algorithms, and vast training datasets, require a specialised and carefully considered approach to incident response.
Disruption of Algorithmic Processes
Incidents that target your AI workflows can disrupt the core of your business operations. A denial-of-service attack or malware infection could compromise model inference capabilities or poison decision-making processes. Your incident response plan must therefore answer critical questions specific to this context. For example: how will your team perform a forensic analysis on a model that is producing anomalous, but not overtly malicious, outputs? How do you collect evidence of data poisoning without compromising the integrity of your entire training pipeline? A plan to restore these critical algorithmic operations swiftly and securely is essential.
Exposure of Sensitive Training Datasets
A data breach involving your sensitive training datasets is one of the most critical incidents you can face. The consequences of such a leak are severe, ranging from reputational damage to significant regulatory penalties. Your incident response plan must have clear, actionable protocols for this scenario. For instance, your plan must detail the procedure for activating legal counsel, quantifying the scope of the exposed Personally Identifiable Information (PII) within the dataset, and initiating the 72-hour notification clock as mandated by regulations like the GDPR.
Vulnerabilities in the AI Supply Chain
Your AI development lifecycle likely relies on a complex supply chain that includes third-party data sources, pre-trained models, and cloud services. An incident originating with one of your suppliers can have a direct impact on your own security. This risk is so significant that it is addressed directly in another part of the standard, ISO 27001 Annex A control 5.21 (Managing Information Security in the ICT Supply Chain). Your incident response process must account for these external dependencies and include clear procedures for coordinating with partners when a vulnerability is discovered.
These heightened risks demand that you develop a formal, documented, and well-rehearsed incident response plan that is tailored specifically to your AI environment.
Your Action Plan: How to Comply with Annex A 5.26
A proactive and structured approach to incident response is not just a compliance exercise; it is a strategic necessity. The following steps provide a clear, actionable framework for building this critical capability within your AI business, ensuring you meet the requirements of Annex A 5.26.
Establish Your Foundation
The first step is to create the formal structures that will guide your response in a crisis.
- Develop a formal Incident Response Plan. This must be a documented set of procedures that outlines how your organisation will identify, assess, contain, and communicate during and after an incident. It must also include procedures for crucial activities like evidence collection and forensic analysis. As an auditor, this documented plan is the first piece of evidence I request to verify compliance with this control.
- Establish a dedicated Incident Response Team. You need to formally designate a team of individuals responsible for executing the plan. This team must consist of people with the necessary technical and organisational skills to manage an incident from detection through to resolution. Clearly defined roles and responsibilities are essential for an effective response.
Implement the Response Lifecycle
Your response must follow a structured lifecycle to ensure no critical step is missed. The key phases and their primary actions are:
| Phase | Action | Goal |
|---|---|---|
| Containment | Isolate affected systems to stop the incident from spreading. | Stop the bleeding. |
| Eradication | Remove the threat and close the vulnerability that allowed it to occur. | Clean the wound. |
| Recovery | Restore systems and services to normal, secure operation. | Get back to work. |
| Communication | Notify relevant stakeholders, such as regulators or customers, as required. | Legal compliance. |
Learn and Improve
The work is not over once an incident is closed. This final phase is critical for building long-term resilience.
- Conduct a post-mortem analysis. After every significant incident, you must perform a review to identify the root cause. This involves analysing what happened, how your team responded, and what could have been done better.
- Commit to continuous improvement. The lessons learned from incidents must be fed back into your security programme. An incident should not be considered fully resolved until it has met strict completion criteria, which includes using your findings to review and improve your incident response processes, technical controls, and organisational policies to prevent the incident from recurring.
Implementing these steps from scratch can be a complex and time-consuming process, but a practical solution exists to accelerate your path to compliance.
The Solution: Achieving Compliance with the High Table Toolkit
Addressing the complexities of incident response, especially within an AI context, requires a robust and reliable foundation. The High Table ISO 27001 Templates Toolkit provides the definitive solution for creating the robust, documented procedures required by Annex A 5.26.
This toolkit helps your AI company achieve compliance by providing a pragmatic, auditor-verified methodology. Key benefits include:
- Provides Documented Procedures: The toolkit includes the essential policies and procedures you need, such as a comprehensive Information Security Incident Management Plan. This provides the formal documentation an auditor will expect to see.
- Clarifies Roles and Responsibilities: The templates guide you in defining and assigning the specific roles and responsibilities required for an effective incident response team, ensuring clarity when an incident occurs.
- Accelerates Implementation: Starting with an expert-designed framework saves your team significant time and effort. Instead of building from scratch, you can leverage a proven structure and focus on tailoring it to your unique AI environment.
- Ensures Full Coverage: The templates are designed by experts to ensure all requirements of the control are met, from documenting containment procedures and evidence collection protocols to establishing a formal process for root cause analysis and continuous improvement.
By using a toolkit, you establish the foundational governance structure you need, allowing you to adapt the documents to your specific AI-related risks and operational workflows with confidence.
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Conclusion: Building Resilience in the AI Era
While the world of artificial intelligence presents unique and evolving security challenges, complying with ISO 27001 Annex A 5.26 is a vital and achievable step toward building genuine organisational resilience. A structured, documented, and practised incident response capability is your best defence against the inevitable.
Ultimately, effective incident response is not just a compliance task. It is a strategic advantage that protects your innovation, your critical data assets, and the trust you have built with your stakeholders. The High Table toolkit provides a clear and efficient path to achieving this, empowering you to manage risks effectively and grow your business securely.
About the author
Stuart Barker is a veteran practitioner with over 30 years of experience in systems security and risk management.
Holding an MSc in Software and Systems Security, Stuart combines academic rigor with extensive operational experience. His background includes over a decade leading Data Governance for General Electric (GE) across Europe, as well as founding and exiting a successful cyber security consultancy.
As a qualified ISO 27001 Lead Auditor and Lead Implementer, Stuart possesses distinct insight into the specific evidence standards required by certification bodies. He has successfully guided hundreds of organizations – from high-growth technology startups to enterprise financial institutions – through the audit lifecycle.
His toolkits represents the distillation of that field experience into a standardised framework. They move beyond theoretical compliance, providing a pragmatic, auditor-verified methodology designed to satisfy ISO/IEC 27001:2022 while minimising operational friction.
