Evidence · DiggingBeagle record
Agentic Browser Security: Indirect Prompt Injection in Perplexity Comet
Primary disclosure of a controlled Comet attack chain, including a mitigation/retesting timeline. Brave is the reporting researcher and a browser vendor; its report is not independent replication of its own experiment. Use the Case to separate the historical result from current-version uncertainty.
- Published
- Aug 20, 2025
- Accessed
- Oct 1, 2026
- Publisher
- Brave
- Source role
- primary disclosure
Evidence record
Primary disclosure of a controlled Comet attack chain, including a mitigation/retesting timeline. Brave is the reporting researcher and a browser vendor; its report is not independent replication of its own experiment. Use the Case to separate the historical result from current-version uncertainty.
Claim-level citations (2)
- supportsPerplexity Comet prompt injection crossed authenticated browser origins: Brave demonstrated an indirect prompt injection embedded in a Reddit comment that was processed when a Comet user invoked the page-summary feature.
Attack demonstration, steps describing the malicious Reddit comment and Summarize action
- supportsPerplexity Comet prompt injection crossed authenticated browser origins: In Brave's proof of concept, injected instructions caused Comet to retrieve the victim's Perplexity account email, initiate an OTP flow, read the OTP from an authenticated Gmail session and exfiltrate the email and OTP through a Reddit reply.
Attack demonstration, numbered sequence covering Perplexity account access, OTP request, Gmail access and Reddit exfiltration