Resource exhaustion in Sgl-Project Sglang
CVE-2026-93838
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.9 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.007 (51.3th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 51st percentile — 51.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.007 · newest: 0.007 · change: 0.000
Affected products
Weakness classification (CWE)
References
- github.com/sgl-project/sglang/issues/39764 (issue-tracking)
- github.com/sgl-project/sglang (product)
- github.com/sgl-project/sglang/blob/v0.5.20/python/sglang/srt/disaggregation/com… (technical-description)
- github.com/sgl-project/sglang/blob/v0.5.20/python/sglang/srt/disaggregation/com… (technical-description)
- github.com/sgl-project/sglang/blob/v0.5.20/python/sglang/srt/disaggregation/com… (technical-description)
- www.vulncheck.com/advisories/sglang-through-0.5.20-unbounded-memory-allocation-… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-93838?
- CVE-2026-93838 is a medium-severity vulnerability in Sgl-Project Sglang, classified under Allocation of Resources Without Limits or Throttling. CVSS score: 5.9/10. Published 2026-09-18.
- How severe is CVE-2026-93838?
- Medium severity. CVSS v3 base score is 5.9 out of 10.