CVE-2026-93838Public exploitNetwork attack vectorHinoki check available

Decode scheduler crash via unbounded chunk index

Published Sep 18, 2026 · Updated Sep 18, 2026

Unbounded memory allocation in SGLang 0.5.20 and earlier allows remote attackers to crash a decode scheduler via a STAGING_REQ frame. handle_staging_req() trusts the frame's chunk_idx and repeatedly appends entries to an in-memory array until that attacker-selected index exists. Exploitation requires TP-mismatch prefill/decode disaggregation, access to the internal decode ZMQ rank port, and a registered bootstrap room; memory exhaustion terminates the decode process.

CVSS severity8.2
High
EPSS probability0.65%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Unbounded memory allocation in SGLang 0.5.20 and earlier allows remote attackers to crash a decode scheduler via a STAGING_REQ frame. handle_staging_req() trusts the frame's chunk_idx and repeatedly appends entries to an in-memory array until that attacker-selected index exists. Exploitation requires TP-mismatch prefill/decode disaggregation, access to the internal decode ZMQ rank port, and a registered bootstrap room; memory exhaustion terminates the decode process.

The record

CVE
CVE-2026-93838
Published
Sep 18, 2026
Updated
Sep 18, 2026
Vendor
SGLang Project
Product
SGLang
Classifications
CWE-770, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 18, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 18, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <=0.5.20

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

SGLang Project · SGLangversion=0 <=0.5.20

Published CVSS scores

8.2VulnCheckCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
5.9VulnCheckCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Activity data is delayed. The latest report is Sep 28, 2026.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-770Allocation of Resources Without Limits or Throttling
T1499Endpoint Denial of Service

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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