sgl-project SGLang up to 0.5.20 Staging Request handle_staging_req chunk_idx allocation of resources

Summaryinfo

A vulnerability has been found in sgl-project SGLang up to 0.5.20 and classified as problematic. This vulnerability affects the function handle_staging_req of the component Staging Request Handler. The manipulation of the argument chunk_idx leads to allocation of resources. This vulnerability is referenced as CVE-2026-93838. Remote exploitation of the attack is possible. No exploit is available.

Detailsinfo

A vulnerability was found in sgl-project SGLang up to 0.5.20 and classified as problematic. This issue affects the function handle_staging_req of the component Staging Request Handler. The manipulation of the argument chunk_idx with an unknown input leads to a allocation of resources vulnerability. Using CWE to declare the problem leads to CWE-770. The product allocates a reusable resource or group of resources on behalf of an actor without imposing any restrictions on the size or number of resources that can be allocated, in violation of the intended security policy for that actor. Impacted is availability. The summary by CVE is:

SGLang versions through 0.5.20 contain an unbounded memory allocation vulnerability in handle_staging_req() that fails to validate chunk_idx from ZMQ STAGING_REQ frames in prefill/decode disaggregation deployments. Attackers with access to the decode engine's internal ZMQ rank port can send a frame with an extremely large chunk_idx value, causing the scheduler to allocate memory until the system runs out and terminates the process.

It is possible to read the advisory at github.com. The identification of this vulnerability is CVE-2026-93838 since 09/18/2026. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. Technical details of the vulnerability are known, but there is no available exploit. The attack technique deployed by this issue is T1499 according to MITRE ATT&CK.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

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Productinfo

Type

• Project Management Software

Vendor

• sgl-project

Name

• SGLang

Version

• 0.5.0
• 0.5.1
• 0.5.2
• 0.5.3
• 0.5.4
• 0.5.5
• 0.5.6
• 0.5.7
• 0.5.8
• 0.5.9
• 0.5.10
• 0.5.11
• 0.5.12
• 0.5.13
• 0.5.14
• 0.5.15
• 0.5.16
• 0.5.17
• 0.5.18
• 0.5.19
• 0.5.20

Website

• Product: https://github.com/sgl-project/sglang/

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