---
id: CVE-2026-93688
title: >-
  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
summary: >-
  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 …
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-770
vendor: sgl-project
product: sglang
affected:
  - sglang <= 0.5.19
published: '2026-09-18'
updated: '2026-09-22'
sourceUpdated: '2026-09-22T20:43:58.793'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-93688'
references:
  - url: 'https://github.com/sgl-project/sglang'
    label: disclosure@vulncheck.com
  - url: >-
      https://github.com/sgl-project/sglang/blob/v0.5.19/python/sglang/srt/disaggregation/mooncake/conn.py#L1988-L1990
    label: disclosure@vulncheck.com
  - url: >-
      https://github.com/sgl-project/sglang/blob/v0.5.19/python/sglang/srt/disaggregation/mooncake/conn.py#L2118-L2119
    label: disclosure@vulncheck.com
  - url: >-
      https://github.com/sgl-project/sglang/blob/v0.5.19/python/sglang/srt/managers/io_struct.py#L281
    label: disclosure@vulncheck.com
  - url: >-
      https://github.com/sgl-project/sglang/blob/v0.5.19/python/sglang/srt/managers/scheduler.py#L2672-L2690
    label: disclosure@vulncheck.com
  - url: 'https://github.com/sgl-project/sglang/issues/39428'
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/sglang-through-0.5.19-unbounded-memory-allocation-via-bootstrap-room
    label: disclosure@vulncheck.com
tags:
  - nvd
  - cve.org
epss: 0.0072
epssPercentile: 0.51923
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-09-21T16:28:51.593250Z'
ingestedAt: '2026-09-18T15:44:31.587Z'
---

## Overview

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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.