Description
SGLang through 0.5.22 with the Mooncake disaggregation backend accepts unauthenticated decode registration messages on the Prefill rank ZMQ PULL socket, allowing denial of service. Network-adjacent attackers can send many registrations with unique mooncake_session_id values and large nested-buffer frames to exhaust Prefill memory until the scheduler is OOM-killed.
Published: 2026-10-19
Score: 7.1 High
EPSS: n/a
KEV: No
Impact: Denial of Service
Action: Patch
AI Analysis

Impact

SGLang versions up to 0.5.22 permit unauthenticated decode registration messages on the Prefill rank ZMQ PULL socket, enabling an attacker to send numerous registrations with unique mooncake_session_id values and large nested‑buffer frames. The resulting memory exhaustion can cause the Prefill scheduler to be OOM killed, disrupting service availability.

Affected Systems

SGLang (sgl-project:sglang) version 0.5.22 and earlier are affected.

Risk and Exploitability

The vulnerability scores a CVSS 7.1, indicating a high impact. EPSS data is unavailable, and the issue is not listed in the CISA KEV catalog. Exploitation requires the attacker to be network‑adjacent and to access the Prefill rank ZMQ PULL socket, sending many registration packets to exhaust memory. No authentication is needed, making the attack relatively straightforward for anyone who can reach the socket.

Generated by OpenCVE AI on October 19, 2026 at 15:46 UTC.

Remediation

No solution or workaround provided in the CVE record.

OpenCVE Recommended Actions

  • Update SGLang to a version newer than 0.5.22 or apply the security patch that addresses the memory exhaustion in the Mooncake backend.
  • Restrict or rate‑limit access to the Prefill rank ZMQ PULL socket so that unauthenticated decode registration traffic cannot flood the system.
  • Monitor memory usage of the Prefill scheduler and configure alerts or automated restarts when OOM conditions are detected.

Generated by OpenCVE AI on October 19, 2026 at 15:46 UTC.

Tracking

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Advisories

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History

Mon, 19 Oct 2026 19:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Mon, 19 Oct 2026 19:15:00 +0000

Type Values Removed Values Added
First Time appeared Sgl-project
Sgl-project sglang
Vendors & Products Sgl-project
Sgl-project sglang

Mon, 19 Oct 2026 14:00:00 +0000

Type Values Removed Values Added
Description SGLang through 0.5.22 with the Mooncake disaggregation backend accepts unauthenticated decode registration messages on the Prefill rank ZMQ PULL socket, allowing denial of service. Network-adjacent attackers can send many registrations with unique mooncake_session_id values and large nested-buffer frames to exhaust Prefill memory until the scheduler is OOM-killed.
Title SGLang through 0.5.22 Memory Exhaustion via Unauthenticated Mooncake Decode Registrations
Weaknesses CWE-770
References
Metrics cvssV3_1

{'score': 6.5, 'vector': 'CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}

cvssV4_0

{'score': 7.1, 'vector': 'CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N'}

Subscriptions

Sgl-project Sglang
cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-10-19T18:06:43.345Z

Reserved: 2026-10-19T13:25:26.990Z

Link: CVE-2026-112269

cve-icon Vulnrichment

Updated: 2026-10-19T18:06:33.708Z

cve-icon NVD

Status : Deferred

Published: 2026-10-19T14:17:04.467

Modified: 2026-10-19T19:17:27.590

Link: CVE-2026-112269

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-10-19T19:00:04Z

Weaknesses
  • CWE-770

    Allocation of Resources Without Limits or Throttling