CRITICAL 9.3 NVD
CVE-2026-85695
FastChat contains an authentication bypass vulnerability in the /register_worker endpoint that allows unauthenticated attackers to register arbitrary worker add
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.
References
- https://github.com/lm-sys/FastChat
- https://github.com/lm-sys/FastChat/blob/v0.2.36/fastchat/serve/controller.py
- https://github.com/lm-sys/FastChat/issues/3886
- https://www.vulncheck.com/advisories/fastchat-unauthenticated-worker-registration-ssrf-and
This critical severity vulnerability with a CVSS score of 9.3 was published on 2026-09-04 via NVD.
Risk Timeline
CVE Disclosed2026-09-04 · -1 days ago
Remediation Resources
vulnfeed aggregates 8217 vulnerabilities from NVD, CISA KEV,
Ubuntu, Debian, Red Hat, Kubernetes, Exploit-DB, OSS-Security, GitHub and OpenStack — updated every 4 hours.