SGLang through 0.5.19 in prefill/decode disaggregation mode contains an unauthenticated PUT /route endpoint on the prefill bootstrap service that allows attackers to poison the KV transfer routing table. Attackers can supply arbitrary rank_ip and rank_port values to redirect decode workers to attacker-controlled endpoints, causing denial of service or disclosure of KV transfer metadata including session identifiers and tensor-parallel topology parameters.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Attack Requirements
None
No additional conditions
Privileges Required
None
No privileges needed
User Interaction
None
No user interaction needed
Impact Assessment
Confidentiality
Low
Partial data leak
Integrity
Low
Partial data modification
Availability
High
Complete denial of service
CVSS Vector v4.0
Weakness Type (CWE)
Vulnerable Products
sgl-project:sglang
References 5
https://github.com/sgl-project/sglang/issues/39400
GitHub Issue #39400
https://github.com/sgl-project/sglang/blob/v0.5.19/python/sglang/srt/disaggrega…
NVD
https://github.com/sgl-project/sglang/blob/v0.5.19/python/sglang/srt/disaggrega…
NVD
https://github.com/sgl-project/sglang
NVD
https://www.vulncheck.com/advisories/sglang-through-0.5.19-unauthenticated-rout…
VulnCheck Advisory: SGLang through 0.5.19 Unauthenticated Route Poisoning via PUT endpoint