ISO 27001 Control 5.27: Learning from Information Security Incidents

What this means

Control 5.27 mandates that your organization establish a formal process to extract lessons from information security incidents and use those lessons to improve your security controls and reduce future risk. This means documenting what happened, why it happened, what impact it had, and—critically—what controls could have prevented it or reduced its severity. The goal is continuous improvement: each incident becomes a data point that makes your security posture stronger.

How to comply

1. 1.Establish an incident response process that captures root cause, impact assessment, and remediation details for every security incident
2. 2.Create a centralized incident log or database that tracks all incidents, including near-misses and low-severity events
3. 3.Conduct post-incident reviews (blameless retrospectives) to identify systemic weaknesses and control gaps
4. 4.Document lessons learned and corrective actions in a way that's accessible to your security team and leadership
5. 5.Map each lesson back to specific controls and determine whether existing controls need strengthening or new controls are required
6. 6.Track the implementation of corrective actions and measure their effectiveness over time
7. 7.Share anonymized incident learnings across teams to prevent similar incidents elsewhere in the organization
8. 8.Review and update your incident knowledge base quarterly to identify patterns and emerging threats

Evidence auditors look for

• Documented incident reports including root cause analysis, timeline, and business impact
• Post-incident review meeting notes with attendees, findings, and agreed corrective actions
• Incident lessons-learned register mapping incidents to control improvements
• Updated control documentation showing changes made as a result of incident learnings
• Evidence of corrective action implementation (e.g., patched systems, updated policies, additional training)
• Quarterly trend reports showing incident frequency, types, and control effectiveness
• Security awareness training materials updated to address lessons from real incidents
• Board or leadership reporting showing how incident learnings improved the security program

Frequently asked questions

GRCWatch's incident tracking module automatically logs and categorizes security incidents, links them to affected controls, and generates post-incident review templates—so you capture lessons in real time instead of scrambling to document them months later.

See how GRCWatch handles this control automatically

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