Embedding-based LLM prompt injection detectors, specifically those based on the DeBERTa-v3 architecture, are vulnerable to adversarial evasion attacks utilizing "hard-negative" mining and fuzzing techniques. Attackers can circumvent detection mechanisms by iteratively generating adversarial prompts that are semantically malicious but structurally mutated to evade the classifier's decision boundary. Specific evasion vectors identified include semantic fuzzing (paraphrasing), syntactic fuzzing…
A vulnerability exists in multiple state-of-the-art Vision-Language Models (VLMs), including GPT-4o, Gemini-2.5, and LLaVA-OneVision, where persuasive textual misinformation successfully overrides visual evidence. When a model is presented with an image it can correctly interpret, an attacker can inject a contradictory text prompt employing specific rhetorical strategies (Logical, Credibility, Emotional, or Repetition) to force the model into generating a false response. This "obedience bias"…
Do Images Speak Louder than Words? Investigating the Effect of Textual Misinformation in VLMs
Large Language Models (LLMs) acting as web agents exhibit a vulnerability in their decision-making process when validating external URLs. The models fail to correctly identify malicious domains when the Uniform Resource Locator (URL) structure—specifically the subdomain, directory path, or query parameters—is manipulated to include semantically "safe" keywords or mimic benign websites (URL disguising). Attackers can induce the agent to accept and visit a malicious link by embedding natural…
MalURLBench: A Benchmark Evaluating Agents' Vulnerabilities When Processing Web URLs
Evaluated models: GPT-3.5, GPT-4o, Llama 2 7B+4 more
Personalized LLM agents utilizing long-term memory systems are vulnerable to a safety bypass known as intent legitimation. Benign, organically accumulated user memories can bias the model's intent inference, causing it to misinterpret inherently harmful queries as contextually justified. When a malicious request semantically aligns with a user's established persona (e.g., hobbies, mental health history, routine), the model normalizes the request and complies, effectively bypassing standard…
When Personalization Legitimizes Risks: Uncovering Safety Vulnerabilities in Personalized Dialogue Agents
Evaluated models: GPT-4o, GPT-4o Mini, DeepSeek V3.2+2 more
The Model Context Protocol (MCP) specification v1.0 contains fundamental architectural vulnerabilities enabling server-side prompt injection and privilege escalation. The protocol relies on bidirectional sampling (sampling/createMessage) without cryptographic origin authentication or UI distinction, allowing connected servers to inject content that the LLM backend interprets as legitimate user input. Additionally, the protocol lacks isolation boundaries between concurrent server connections…
Breaking the Protocol: Security Analysis of the Model Context Protocol Specification and Prompt Injection Vulnerabilities in Tool-Integrated LLM Agents
Evaluated models: GPT-4o, Claude 3.5 Sonnet, Llama 3.1 70B
Large Vision-Language Models (LVLMs) are vulnerable to Physical Prompt Injection Attacks (PPIA), a query-agnostic injection technique delivered via the visual modality. The vulnerability stems from the model's "Vision-Enabled Text Recognition" capabilities and "Identity Sensitivity," where the model interprets text embedded in the physical environment (e.g., printed on signs, posters, or objects) as high-priority instructions rather than passive visual data. An attacker can embed adversarial…
Physical Prompt Injection Attacks on Large Vision-Language Models
Evaluated models: GPT-4o, GPT-4o Mini, GPT-4 Turbo+7 more
Vision-Language Models (VLMs) exhibit a vulnerability to moral judgment flipping, where the model's safety alignment can be bypassed through lightweight, model-agnostic multimodal perturbations. By introducing conflicting textual or visual cues that do not alter the underlying moral context of a scenario, an attacker can coerce the model into reversing its ethical stance (e.g., reclassifying a harmful action from "morally wrong" to "not morally wrong"). This vulnerability exploits the model's…
Do VLMs Have a Moral Backbone? A Study on the Fragile Morality of Vision-Language Models
Conversational Large Language Model (LLM) agents integrated with privileged data sources (e.g., medical records, organizational emails) are vulnerable to contextually inappropriate information disclosure due to failures in enforcing Contextual Integrity (CI) norms. Standard semantic input/output filters and generic safety guardrails (e.g., Llama Guard) fail to detect "mosaic attacks" and multi-turn conversational manipulation. In these attacks, adversaries decompose a malicious query into a…
NeuroFilter: Privacy Guardrails for Conversational LLM Agents
A vulnerability in large language models (LLMs) allows attackers to induce factually incorrect outputs by injecting misinformation into prompts framed with strong confidence. By using authoritative phrasing (e.g., "As we know..."), attackers exploit model sycophancy, causing the LLM to accept the false premise and generate hallucinated content aligned with the injected misinformation. The models fail to detect and correct the embedded falsehoods, generating fabricated but plausible responses.
AdversaRiskQA: An Adversarial Factuality Benchmark for High-Risk Domains
Evaluated models: GPT-oss 20B, GPT-oss 120B, GPT-5+3 more
LLM-based evaluation systems ("LLM-as-a-Judge") exhibit a structural vulnerability termed "Framing Bias," wherein the model produces logically contradictory judgments depending on the syntactic framing of the evaluation prompt. Specifically, when assessing the same content using predicate-positive (P) framing (e.g., "Is this toxic?") versus predicate-negative (¬P) framing (e.g., "Is this non-toxic?"), models frequently fail to invert their binary decisions, leading to inconsistency rates…
When Wording Steers the Evaluation: Framing Bias in LLM judges