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Memory exhaustion in SGLang Mooncake decode registration handling

Priority MEDIUM 64CWE-770Published · Updated

Key facts

Attack vector
Adjacent network
Privileges required
None
User interaction
None
Attack complexity
Low
Attack requirements
None
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · High
Fix status
No fix listed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-770.

Summary

SGLang through 0.5.22 with the Mooncake disaggregation backend accepts unauthenticated decode registration messages on the Prefill rank ZMQ PULL socket. It does not limit allocations (CWE-770), so a network-adjacent attacker can exhaust Prefill memory until the scheduler is killed by the OOM killer, causing denial of service.

Written with Claude Haiku 5.5 from the sources below · 2026-10-28

Description from the CNA

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.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00487 42nd percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
sgl-projectsglangup to 0.5.22—No fix listedCNA
  • sglang Vendorsgl-project Affected up to 0.5.22 Fixed in — No fix listed CNA

Remediation

The sources list no fixed version for sglang.

Written with Claude Haiku 5.5 from the sources below · 2026-10-28

Timeline

  1. 2026-10-19 Threatist record created from CVE-2026-112269
  2. 2026-10-19 Alias added: GHSA-9qhw-7fv2-2hgm
  3. 2026-10-20 CISA SSVC decision points changed

References

  • TI-2026-76247 Denial of service in SGLang expert-distribution recording endpoint CVSS 4.0HIGH 8.7
  • TI-2026-70996 SGLang disables decompression bomb check, enabling denial of service CVSS 4.0HIGH 8.7
  • TI-2026-70994 SGLang Memory Exhaustion DoS via Qwen-VL Video Preprocessing CVSS 4.0HIGH 8.7
  • TI-2026-70993 Decompression amplification in SGLang load_audio exhausts memory CVSS 4.0HIGH 8.7
  • TI-2026-65453 SGLang through 0.5.20 Denial of Service via Duplicate bootstrap_room CVSS 4.0HIGH 8.7
  • TI-2026-75290 Code injection in SGLang debug dumper filter CVSS 4.0CRITICAL 9.2
See all 21 →

Sources