Grok chat duped into swallowing injected instructions
A spoonful of encryption helps the malware go down
xAI's Grok web chat agent is susceptible to a novel form of prompt injection, according to security researchers from Adversa AI. This technique, known as cryptographic context injection, involves injecting malicious instructions into a web page that are encrypted and accompanied by an encryption key. The AI model, during its summarization process, decrypts the instructions using the provided key within its own code execution sandbox.
This allows the model to carry out harmful actions, as the guardrail scanner fails to detect the encrypted text. The Adversa researchers demonstrated this vulnerability by showing how the attack can be used to exfiltrate a user's chat history with Grok.com, including personal information and prompts. Adversa informed xAI about the attack on June 3, 2026, but no mitigation timeline was provided.
The attack remains effective as of August 19, 2026. Google was not informed of the attack, as it considers jailbreaks to be out of scope for its vulnerability disclosure program.
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- Grok chat duped into swallowing injected instructions theregister.com
