CVE-2026-93838
SGLang through 0.5.20 Unbounded Memory Allocation via STAGING_REQ chunk_idx
CVSS Score
5.9
EPSS Score
0.0%
EPSS Percentile
0th
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.
| CWE | CWE-770 |
| Vendor | sgl-project |
| Product | sglang |
| Published | Sep 18, 2026 |
| Last Updated | Sep 18, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H Attack Vector
Network
Attack Complexity
High
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High
Affected Versions
sgl-project / sglang
0 ≤ 0.5.20
References
github.com: https://github.com/sgl-project/sglang/issues/39764 github.com: https://github.com/sgl-project/sglang github.com: https://github.com/sgl-project/sglang/blob/v0.5.20/python/sglang/srt/disaggregation/common/staging_handler.py#L781 github.com: https://github.com/sgl-project/sglang/blob/v0.5.20/python/sglang/srt/disaggregation/common/staging_handler.py#L848-L860 github.com: https://github.com/sgl-project/sglang/blob/v0.5.20/python/sglang/srt/disaggregation/common/conn.py#L1636-L1640 vulncheck.com: https://www.vulncheck.com/advisories/sglang-through-0.5.20-unbounded-memory-allocation-via-staging-req-chunk-idx
Credits
🔍 Jiapeng Li 🔍 Mingkai Yu 🔍 Jiajia Liu