Straight answer
Will prompt injection ever be fully fixed?
Probably not. The NCSC and OpenAI have both said a complete fix may never arrive, so plan to contain it.
Last reviewed against NCSC, OWASP GenAI Security Project and Microsoft Security Response Center. Sources
The answer
Two authorities, one view
The NCSC expects that this attack will never be shut down as thoroughly as SQL injection was, and says the best available outcome is to lower the likelihood or the impact of attacks [1]. OpenAI, writing about its Atlas browser, said the problem is unlikely ever to be fully "solved", and compared it to scams and social engineering on the web [5].
What continues
The work is not stopping
OpenAI described a reinforcement-learning attacker that it uses to hunt for new attack methods, and said it turned up strategies that earlier red teaming had missed [5]. Microsoft describes layered prevention, detection and impact mitigation, built on the assumption that some injections will get through [3].
None of this means defences are pointless. It means the design should expect an occasional failure.
What it means
Decisions for you
Accept a residual risk, give it a named owner and choose designs that survive a bad instruction. Where that is not acceptable, the NCSC says an LLM may be the wrong tool for the job [1].
Three questions help a board decide:
- What is the worst thing this tool could be talked into doing?
- Who would notice, and how soon?
- Does a person or a fixed rule stand in the way?
See how to reduce the risk, and the comparison with SQL injection for the reasoning.
A caution on claims
The NCSC advises being wary of vendors who say they can "stop" prompt injection [1].
Keep reading
Read next
Do filters work?
Do prompt injection filters, deny-lists and detection products work? What the NCSC, OWASP and Microsoft say about their value and their limits.
Read the guide
Detecting it
How to spot prompt injection attempts: what to log, which signals to watch and why failed tool calls matter, based on NCSC and Microsoft guidance.
Read the guide
Questions
Short, sourced answers on prompt injection: what it is, whether it can be fixed, how it differs from SQL injection and what UK teams should do first.
Read the guideHow CyPro can help
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Prompt injection only shows up when someone tries it against your own tools. Penetration testing can probe the AI features you run or build, to see what a hostile instruction could reach.