---
id: CVE-2026-102634
title: >-
  SGLang through 0.5.20 in prefill/decode disaggregation mode fails to validate
  duplicate bootstrap_room fields in /generate requests with Mooncake KV
  transfer backend
summary: >-
  SGLang through 0.5.20 in prefill/decode disaggregation mode fails to validate
  duplicate bootstrap_room fields in /generate requests with Mooncake KV
  transfer backend. Unauthenticated attackers can send concurrent requests with
  identical …
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-694
vendor: sgl-project
product: sglang
affected:
  - sglang <= 0.5.20
published: '2026-09-29'
updated: '2026-09-29'
sourceUpdated: '2026-09-29T17:17:07.280'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-102634'
references:
  - url: 'https://github.com/sgl-project/sglang'
    label: disclosure@vulncheck.com
  - url: >-
      https://github.com/sgl-project/sglang/blob/v0.5.20/python/sglang/srt/disaggregation/common/conn.py#L392-L393
    label: disclosure@vulncheck.com
  - url: >-
      https://github.com/sgl-project/sglang/blob/v0.5.20/python/sglang/srt/disaggregation/decode.py#L942
    label: disclosure@vulncheck.com
  - url: >-
      https://github.com/sgl-project/sglang/blob/v0.5.20/python/sglang/srt/disaggregation/mooncake/conn.py#L2760-L2764
    label: disclosure@vulncheck.com
  - url: >-
      https://github.com/sgl-project/sglang/blob/v0.5.20/python/sglang/srt/managers/io_struct.py#L281
    label: disclosure@vulncheck.com
  - url: 'https://github.com/sgl-project/sglang/issues/40125'
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/sglang-through-0.5.20-denial-of-service-via-duplicate-bootstrap-room
    label: disclosure@vulncheck.com
tags:
  - nvd
  - cve.org
  - exploit-available
exploitAvailable: true
ssvc:
  exploitation: poc
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-09-29T17:33:03.800231Z'
ingestedAt: '2026-09-29T16:39:33.278Z'
---

## Overview

SGLang through 0.5.20 in prefill/decode disaggregation mode fails to validate duplicate bootstrap_room fields in /generate requests with Mooncake KV transfer backend. Unauthenticated attackers can send concurrent requests with identical bootstrap_room values to crash scheduler processes or hang other users' requests until transfer timeout.

## Remediation

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