7.5High
CVE-2026-93688
SGLang through 0.5.19 in prefill/decode disaggregation mode with Mooncake KV transfer backend fails to validate bootstrap_room values, allowing unbounded transfer state allocation. Unauthenticated attackers can reach the decode engine's POST /generate endpoint and submit arbitrary bootstrap_room values to exhaust prefill process memory until out-of-memory termination.
What this means for your business
- An attacker can use it remotely, over a network, without a login, and without anyone at your company clicking anything.
What to do
- 1Ask your IT team or provider whether any of your systems use the affected product.
- 2If you do, follow the vendor's guidance. No patch reference has been published yet.
Not sure if your company is exposed?
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Scoring
- CVSS
- 7.5 (v3.1)
- Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H- CVSS v4
- 8.7
- Weakness
- CWE-770
- Assigned by
- disclosure@vulncheck.com
Dates
- Published
- 2026-09-18
- Last modified
- 2026-09-21
- Sources
- NVD
References
- https://github.com/sgl-project/sglang
- https://github.com/sgl-project/sglang/blob/v0.5.19/python/sglang/srt/disaggregation/mooncake/conn.py#L1988-L1990
- https://github.com/sgl-project/sglang/blob/v0.5.19/python/sglang/srt/disaggregation/mooncake/conn.py#L2118-L2119
- https://github.com/sgl-project/sglang/blob/v0.5.19/python/sglang/srt/managers/io_struct.py#L281
- https://github.com/sgl-project/sglang/blob/v0.5.19/python/sglang/srt/managers/scheduler.py#L2672-L2690
- https://github.com/sgl-project/sglang/issues/39428
- https://www.vulncheck.com/advisories/sglang-through-0.5.19-unbounded-memory-allocation-via-bootstrap-room