CVE-2026-85695

FastChat contains an authentication bypass vulnerability in the /register_worker endpoint that allows unauthenticated attackers to register arbitrary worker addresses and perform server-side request forgery. Attackers can register malicious workers under victim model names to intercept user prompts, images, and responses, or probe internal network ports across the worker mesh.

  • Published Sep 4, 2026
  • CVSS 9.3 critical
  • 0.7% chance of exploitation in the next 30 days (EPSS)

Affected software

CVE-2026-85695 at the National Vulnerability Database