ZeroHour

Search: “chat template poisoning”

7 stories

A Malicious Webpage Could Poison Your Local AI Model Behind NVIDIA NemoClaw

Oasis Security found NVIDIA NemoClaw's Ollama binding to 0.0.0.0 enables DNS rebinding attacks that let attacker pages poison model chat templates with persistent hidden instructions.

Oasis Security disclosed that NVIDIA NemoClaw on Windows/WSL paths binds Ollama to 0.0.0.0:11434 without authentication, exposing the API to browser-based DNS rebinding attacks from malicious webpages. An attacker can then modify the model's chat template via /api/create, planting hidden instructions that run on every subsequent inference and persist across conversations, invisible to API consumers. NemoClaw v0.0.35 fixed the issue on macOS and Linux; no fix exists for Windows and WSL paths beyond a warning in v0.0.34. Ollama's own 2024 fix (CVE-2024-28224) added Host header validation, but it is skipped when bound to non-loopback addresses. No exploitation has been reported as of August 25, 2026.

New Cryptographic Context Injection Attack Could Let Web Pages Steal Grok Chat Data

Adversa AI demonstrated 'Cryptographic Context Injection' making xAI's Grok leak chat history and session data to attacker-controlled servers via encrypted web payloads.

Adversa AI disclosed a technique where a web page carries an encrypted JSON object (PBKDF2 and AES-256-GCM) that Grok's code-execution runtime decrypts, letting attacker instructions bypass content classifiers and reach the model's context. The decrypted instructions direct Grok to embed the user's name, approximate location, subscription tier and ongoing conversation into a URL it fetches, exfiltrating the data without confirmation. Testing targeted grok.com running Grok 4.5 Fast on August 19, 2026, with a reported 40% success rate over 20 attempts since June; no CVE, patch, or in-the-wild exploitation is reported. A related demonstration reproduced Gemini 3 Flash system instructions via a fabricated Python traceback, while GPT-5 failed to parse the payload and Claude Sonnet 4.5 flagged it as prompt injection.

The Hacker News · 27d agoAI safety & security