CVE-2026-92972
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.
Weakness
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.
References
- https://github.com/sgl-project/sglang
- https://github.com/sgl-project/sglang/blob/v0.5.19/python/sglang/srt/disaggregation/common/conn.py#L1716-L1718
- https://github.com/sgl-project/sglang/blob/v0.5.19/python/sglang/srt/disaggregation/common/conn.py#L1736-L1810
- https://github.com/sgl-project/sglang/issues/39400
- https://www.vulncheck.com/advisories/sglang-through-0.5.19-unauthenticated-route-poisoning-via-put-endpoint
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