Latest
IBM publishes its 2025 Cost of a Data Breach research[5]
The study looked at AI security and governance for the first time and reported on the cost of shadow AI and missing access controls.
Timeline
AI data breach timeline
There is no single AI data breach to track. This timeline lists the public cases and the guidance published around them, oldest first.
Last reviewed against legislation.gov.uk, National Cyber Security Centre and OWASP GenAI Security Project. Sources
How to read it
A pattern, not one event
The entries below are separate cases with different causes: a software bug, staff uploading code and an open database. Each is sourced to the body that reported it.
What it shows
Three lessons
Suppliers can fail too
The ChatGPT bug was in an open-source library, not in anything the affected users did [7].
Staff behaviour matters
Samsung's response was to restrict tools after staff uploaded source code [8].
Basics still apply
The open DeepSeek database had no authentication [6]. Read exposed AI databases for the checks.
Timeline
How it unfolded
Newest first. Each entry links to its source.
-
-
Wiz reports an open DeepSeek database[6]
Wiz said a publicly accessible ClickHouse database with no authentication held over a million log entries, including chat history and API keys. DeepSeek secured it after disclosure.
-
NCSC publishes AI and cyber security guidance for leaders[3]
The guidance covers data risks, supply chains, prompt injection and the need for a response plan for serious AI-related incidents.
-
NCSC publishes secure AI development guidelines[2]
The NCSC, working with CISA and agencies from other countries, published version 1.0 of guidelines covering design, development, deployment and operation of AI systems.
-
Samsung restricts generative AI tools[8]
Reporting said Samsung banned staff from using generative AI tools on company devices and networks after engineers uploaded internal source code to ChatGPT in April.
-
OpenAI explains the cause[7]
OpenAI attributed the incident to a bug in redis-py, said about 1.2% of ChatGPT Plus subscribers active in the window were affected and said it was contacting those whose payment information was exposed.
-
ChatGPT bug exposes some subscribers' details[7]
For nine hours, from 1am to 10am Pacific time, a bug in an open-source library showed some users other users' chat queries and payment details.
-
ICO updates its AI and data protection guidance[9]
The ICO published updates covering data protection impact assessments, transparency, lawfulness and fairness for AI.
Keep reading
Read next
Shadow AI
How staff use of unapproved AI tools leaks company and personal data, what IBM and Samsung's experience show, and how to find and reduce it.
Read the guide
Exposed databases
What Wiz found in an open DeepSeek database, why it matters for any AI service and the checks UK teams can make on their own AI data stores.
Read the guide
Prompt leaks
How an LLM can disclose personal or confidential data through its outputs, what OWASP and the NCSC advise, and the design choices that limit it.
Read the guideHow CyPro can help
Need a hand working through this?
Finding out whether an incident reaches you is one job. Checking your own systems, tightening access and briefing the board are several more. CyPro's responders and consultants can take any of them on.
Incident response
If you may already be compromised, our responders contain it, preserve the evidence, find out what was touched and get you running again safely.
More on cypro.co.uk
24/7 security monitoring
Our SOC analysts watch your systems day and night for the signs of an attack in progress: unexpected processes, new outbound connections, logins that do not fit.
More on cypro.co.uk
Fractional CISO for the board
A senior security lead who advises the board on what to fix first, what to accept and what to tell customers, and owns the decision record.
More on cypro.co.uk
Penetration testing
A focused test of your systems and the controls around them, so you know they hold before an attacker finds out for you.
More on cypro.co.uk
Hardening and segmentation
Our consultants put the controls in place that limit the damage when something is missed: firewall rules, network isolation and tighter admin access.
More on cypro.co.uk
Vulnerability scanning
Find every internet-facing system you run, including the forgotten ones, and see which are still on a vulnerable build.
See the scanning service
Talk to a specialist
Worried this affects you?
If data has leaked through an AI tool or an exposed AI database, the first hours decide how much is lost and what you must report. An incident response team helps you contain it, work out what was exposed and meet your notification duties.