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
Last Modified:Sep 4, 2026
EPS:Sep 4, 2026
EPSS Score:
CVSS Score:9.4
Affected Products
Vendor
Product
Action
Vendor
Lm-sys
Product
Fastchat
Lm-sys
Fastchat
Exploits
No exploit reference
Common Weakness Enumeration
Common Attack Pattern Enumeration and Classification (CAPEC)
Related CVEs
Common Vulnerability Scoring System
Attack Vector
Network
Adjacent
Local
Physical
Privileges Required
None
Low
High
User Interaction
None
Required
Scope
Unchanged
Changed
Confidentiality
None
Low
High
Integrity
None
Low
High
Availability
None
Low
High
