Securing LLMs in 2025: OWASP, EU AI Act, and Guardrails

Explore how OWASP's Top 10, the EU AI Act, and Promptention's adaptive security platform shape the future of LLM safety and compliance.

Risks and Regulations Collide

The explosive adoption of large language models (LLMs) and generative AI tools has outpaced the security protocols and legal frameworks that typically govern new technologies. In the rush to deploy LLMs into production environments, many organizations have found themselves unprepared for the new wave of risks these models.

In 2025, we are no longer asking whether LLMs should be regulated—we are deep in the process. With the OWASP Top 10 for LLM Applications and the enforcement of the EU AI Act, the pressure on companies to align their AI deployments with best practices and regulatory expectations has never been greater.

This blog breaks down:

  • What OWASP's Top 10 list reveals about the evolving threat landscape
  • What the EU AI Act mandates for LLM developers and users
  • Why guardrails are not optional but essential
  • How Promptention helps enterprises stay ahead of both threats and compliance standards

What Is OWASP and Why Their Top 10 List Matters for AI

The Open Worldwide Application Security Project (OWASP) is a globally recognized authority on cybersecurity best practices. While originally focused on traditional web application threats (e.g., SQL injection, XSS), OWASP has now turned its attention to the unique risks posed by large language models.

Their "Top 10 for LLM Applications", published in 2024 and widely adopted in 2025, is designed to raise awareness of the most pressing security vulnerabilities in AI systems. It serves as both a cautionary checklist and a practical guide for organizations deploying LLMs.

Here's a summary of OWASP's Top 10 LLM risks:

  • Prompt Injection – Malicious prompts manipulate the LLM to override its intended behavior.
  • Insecure Output Handling – Generated content can lead to unintended actions or leaks when consumed by downstream systems.
  • Training Data Poisoning – Attackers insert malicious data during model training to alter behavior.
  • Model Denial of Service (DoS) – Repetitive or oversized prompts that overload the model.
  • Supply Chain Vulnerabilities – Risks arising from dependencies on third-party LLM components.
  • Excessive Agency – Granting LLMs too much control (e.g., autonomous actions without oversight).
  • Over Reliance on LLM Output – Blind trust in model responses can lead to critical errors.
  • Data Leakage via Context – Private or sensitive data unintentionally included in prompt or response history.
  • Insecure Plugin Use – Vulnerabilities introduced through LLM extensions or integrations.
  • Model Theft or Reverse Engineering – Exfiltration of model weights or architecture for malicious use.

These risks are not just theoretical. LLMs must be treated as dynamic, adversarial systems—not static tools.

The EU AI Act: What It Requires in 2025

The EU AI Act, passed in 2024 and entering phased enforcement in 2025, is the world's most comprehensive regulation of artificial intelligence to date. It introduces a risk-based framework to classify AI systems and impose corresponding requirements.

Key elements relevant to LLMs and GenAI applications:

  • High-Risk Classification: LLMs used in legal scoring, recruitment, finance, healthcare, or public services are often deemed high-risk, requiring detailed documentation, risk assessments, and real-time monitoring.
  • Transparency Obligations: Users must be notified when they're interacting with an AI system, especially in decision-making contexts.
  • Robustness and Accuracy: Providers must implement safeguards against manipulation (e.g., prompt attacks), error propagation, and misuse.
  • Traceability and Logging: All interactions may require logging for post-hoc analysis and regulatory audit.
  • Data Governance: Training data must be vetted for bias, legality, and appropriateness.

The AI Act has also triggered a broader international regulatory movement. It aligns closely with global principles from OECD and intersects with GDPR in areas like data protection, automated profiling, and explainability.

Violations can carry fines of up to €35 million or 7% of global turnover—making compliance not just ethical but financially critical.

The Risks in Context: Why Guardrails Are Needed

The technical and legal risks now go hand in hand. Consider these real-world examples:

  • In 2023, attackers embedded hidden instructions into user profiles, leading customer service LLMs to reveal internal company data.
  • A healthcare chatbot trained with sensitive patient records was prompted to disclose symptoms and private information with minimal effort.
  • A RAG-based assistant used in legal discovery was tricked into summarizing and misrepresenting evidence through retrieval pollution.

These incidents aren't hypothetical—they reflect what's already happening. And as LLMs become more powerful, their ability to trigger business logic, touch real data, or interface with critical infrastructure means the cost of failure will only rise.

Traditional defenses—blocklists, regex filters, and input validation—are insufficient in a world where attacks evolve at the speed of language. Companies require threat detection systems and risk management systems.

Promptention's Approach: Secure by Design, Adaptive by Default

At Promptention, we've built our platform to meet the evolving needs of LLM security in both enterprise and regulatory environments.

We provide:

  • Prompt monitoring and logs across all applications
  • PII detection
  • Strict prompt injection detection, adaptable to new attack types
  • Customizable security policies for different business units
  • Real-time alerts with contextual scores, reducing noise and false positives

Our detection layer evolves daily, powered by a rich and expanding dataset of adversarial examples. We do not rely on static filters. Our platform is built not just to respond but to anticipate any kind of prompt attacks.

Whether you're preparing for an EU AI Act audit, mitigating OWASP-class threats, or simply trying to protect your company from reputational risk, Promptention offers a solution that's proactive, precise, and ready for scale.

Conclusion

The convergence of regulation (EU AI Act, GDPR), frameworks (OWASP), and rising enterprise deployment has changed the equation. Security for LLMs is no longer optional. It's foundational.

Guardrails must be:

  • Flexible enough to evolve with adversarial techniques
  • Precise enough to minimize business disruption
  • Context-aware enough to recognize real threats from normal queries

Promptention is here to protect it.

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