Chronicle/Attacks & incidents

Brave finds screenshot and navigation prompt injections in Comet and Fellou browsers

AttackVulnerability disclosureSignificance assistant-drafted

Brave reports that Comet could read faint, low-contrast text embedded in images when a user asked about a screenshot, and that Fellou sent visited page text to its model on simple navigation, letting on-page instructions override user intent. Brave argues both let untrusted content trigger actions under the user's authenticated sessions.

Why it matters

Injection surfaces in agentic browsers extend beyond page text to images and routine navigation.

Key facts

As stated in the sources, with where to find them.

  • Disclosure windows: Perplexity 2025-10-01 to 2025-10-21; Fellou 2025-08-20 to 2025-10-21.Disclosure timeline

Findings that cite this record

Key questions this bears on

Sources

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