Is CVE-2026-93838 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-93838 being exploited in the wild.

How severe is CVE-2026-93838?

Medium severity, with a CVSS score of 5.9, published 18 September 2026.

Which products and versions are affected?

SGLang Project SGLang through 0.5.20.

Is there a fix for CVE-2026-93838?

No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

How is CVE-2026-93838 attacked?

It is attacked over the network.

Am I affected by CVE-2026-93838?

Check whether you run SGLang Project SGLang at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-93838: SGLang unbounded memory allocation in handle_staging_req

CVE-2026-93838 · Severity: medium · CVSS 5.9 · Published 2026-09-18

SGLang is a high-performance serving framework for large language models that can be deployed in a distributed configuration with separate prefill and decode engines. An unbounded memory allocation vulnerability in the decode engine allows attackers with access to internal communication channels to send a specially crafted message that causes the scheduler to allocate memory until the system runs out of resources, leading to service denial. This affects deployments that use prefill/decode disaggregation.

Technologies: SGLang Project SGLang. Vendors: SGLang Project.

Quick answers

Is CVE-2026-93838 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-93838 being exploited in the wild.
How severe is CVE-2026-93838?: Medium severity, with a CVSS score of 5.9, published 18 September 2026.
Which products and versions are affected?: SGLang Project SGLang through 0.5.20.
Is there a fix for CVE-2026-93838?: No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
How is CVE-2026-93838 attacked?: It is attacked over the network.
Am I affected by CVE-2026-93838?: Check whether you run SGLang Project SGLang at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

The handle_staging_req() function in SGLang fails to validate the chunk_idx parameter from ZMQ STAGING_REQ frames, allowing an attacker to supply an arbitrarily large value that triggers unbounded memory allocation in the scheduler. The vulnerability requires network access to the decode engine's internal ZMQ rank port, which is typically only available in multi-node disaggregated deployment topologies. The attack causes denial of service by exhausting memory and forcing process termination.

Affected products

SGLang Project SGLang through 0.5.20

Timeline

2026-09-18: disclosed

References

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