System prompt hardening
What’s really running your AI? Expose and harden it.
Challenges
Hidden doesn’t mean harmless
System prompts are the hidden logic governing your AI’s behavior and create a massive attack surface. Weak instructions open doors for injection and data leaks.
Invisible instruction sets
System prompts operate behind the scenes, hidden from traditional scanners. This creates a critical visibility gap, leaving core AI logic unmonitored and unprotected.
Unquantifiable security risks
Without standardized metrics, security teams cannot measure vulnerability severity. This makes it extraordinarily difficult to prioritize risks or justify security resources to leadership.
No hardening standard
Developers lack a formal playbook for securing AI instructions. This absence of standards leads to inconsistent logic, increasing the risk of injection and data leaks.
Opportunities
Quantifiable system prompt defense
By detecting hidden prompts and applying a formal scoring standard, invisible vulnerabilities can be effectively prioritized and secured.
Instant visibility & labeling
Automatically detect hidden prompts and gain immediate context. By labeling prompts as “conversational,” teams can quickly identify specific attack vectors and prioritize high-risk components.
Standardized AIWE scoring
Stop guessing which threats matter. AI Weakness Enumeration (AIWE) provides a 1–100 score, allowing you to prioritize the most critical AI security risks objectively.
Proactive logic hardening
Automatically refine prompt logic to close security gaps. This ensures your AI applications are resistant to adversarial manipulation and protected against unauthorized data exposure.
The solution
Mend AI
Mend AI tests against threats like prompt injection, context leakage, and data exfiltration to uncover AI behavioral risks unique to your application.
Discover Mend AI
“One of our most indicative KPIs is the amount of time for us to remediate vulnerabilities and also the amount of time developers spend fixing vulnerabilities in our code base, which has reduced significantly. We’re talking about at least 80% reduction in time.”
“When the product you sell is an application you develop, your teams need to be fast, secure and compliant. These three factors often work in opposite directions. Mend provides the opportunity to align these often competing factors, providing Vonage with an advantage in a very competitive marketplace.”
“The biggest value we get out of Mend is the fast feedback loop, which enables our developers to respond rapidly to any vulnerability or license issues. When a vulnerability or a license is disregarded or blocked, and there is a policy violation, they get the feedback directly.”
FAQs
How does Mend.io harden system prompts?
Mend AI automatically detects system prompts in code, identifies weaknesses using the AI Weakness Enumeration framework, and generates hardening suggestions for the prompt. During red teaming tests, the risks identified based on runtime AI behavior drive system prompt hardening suggestions. This system prompt mitigation guidance is designed to guard against the exhibited weaknesses.
How does Mend.io’s AIWE scoring prioritize prompt risk?
AI Weakness Enumeration, or AIWE, is Mend.io’s proprietary framework for system-prompt security, built using the same principles as Common Weakness Scoring System (CWSS). It classifies recurring prompt weaknesses and assigns each identified issue a 1-100 severity score based on factors such as exploitability and potential impact, giving security teams a familiar and consistent way to prioritize which prompt risks to address first.
How does Mend AI find prompt risks that AppSec tools miss?
Traditional SAST and SCA tools focus primarily on source-code vulnerabilities and dependency risk. Mend AI analyzes the instructions and structure within system prompts for AI-specific weaknesses, such as failing to distinguish trusted instructions from user input, missing instruction hierarchies, inadequate protections against persona switching, and secrets embedded in prompts. These weaknesses can influence application behavior without appearing as conventional code vulnerabilities.
For the full background, read what system prompt hardening is and how it secures LLMs.
Can Mend.io find system prompts I don’t know exist?
Yes. Mend AI automatically discovers and inventories system prompts across your applications. It can also identify prompts associated with conversational interfaces, helping teams surface previously unknown prompt-layer attack surfaces.
Does Mend.io’s system prompt hardening prevent prompt injection?
Mend.io reduces prompt-injection risk on both sides of the SDLC. Before deployment, System Prompt Hardening identifies insecure instructions and recommends stronger prompt logic, while automated red teaming tests whether adversarial inputs can still manipulate the application. After deployment, Mend AI Runtime Protection inspects prompts and responses for injection and jailbreak attempts and can alert, block, or obfuscate content according to policy. Together, these controls help teams harden, validate, and defend AI applications continuously.
