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YionStack
Incident response · UK GDPR Articles 33–34

When something goes wrong, here's what we do.

This is the public summary of YionStack's incident response procedure — the playbook our on-call follows when a security or personal-data incident is suspected. It is the operational counterpart to Clause 8 of our DPA.

Last updated: 10 June 2026

Severity bands

Severity drives the response — who's on the bridge, what we tell you, and how fast.

P1 — critical

Active confirmed breach of customer data, total service outage, or active exploitation. All-hands; founder on the bridge.

Example: Authentication bypass exposing business data; ransomware on production

P2 — high

Likely breach, partial outage of a critical service, or vulnerability with confirmed exploit path. Engineering on-call leads.

Example: RLS misconfiguration on a non-default code path; partial Stripe webhook failure

P3 — moderate

Suspected issue with limited customer impact, or vulnerability without confirmed exploit. On-call investigates within working hours.

Example: Spike in 5xx errors on a single endpoint; leaked non-secret config value

The clock from declaration

The moment we declare an incident the timeline below starts running. Every step has an owner; every step is logged for the post-mortem.

  1. T+0
    01. Detect

    Automated alert, support report, or internal escalation. The on-call engineer opens the incident, declares severity, and creates a war room channel.

  2. T+15min
    02. Contain

    First action is always containment — revoke compromised credentials, isolate affected services, freeze suspect businesses. Stop the bleed before forensics.

  3. T+1hr
    03. Triage

    Confirm scope: what data, whose data, which businesses, what timespan. Document everything for the post-mortem and for any required regulator submission.

  4. T+24hr
    04. Notify customers

    For any incident affecting customer data we notify the affected controllers. Notification includes nature, categories of data subjects affected, likely consequences, and our containment.

  5. T+72hr
    05. ICO submission window closes

    Where the breach is likely to result in a risk to data subjects' rights, the controller (you) must notify the ICO within 72 hours of awareness. Our notification is the trigger of your clock.

  6. T+48hr post-resolve
    06. Public retrospective

    For any incident we announced, we publish a retrospective on /status within 48 hours of resolution. What broke, how we found it, what we changed.

What our customer notification contains

When we notify you of a personal-data breach, the message contains the information required by Article 33(3) UK GDPR so you can pass it through to the ICO without having to dig:

  • The nature of the breach
  • The categories and approximate number of data subjects concerned
  • The categories and approximate number of records concerned
  • The likely consequences of the breach
  • The measures we have taken or propose to take to address it
  • Contact details of our data-protection point of contact

If we cannot provide all the information at the time of notification we provide it in phases as it becomes available — Article 33(4) explicitly allows phased notification.

Suspect a breach affecting your business?

Tell us immediately.

We'd rather investigate a false alarm than miss the real one. The same address is listed in your DPA and on /status.

security@yionstack.co.uk