{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "extracted_events": [
              {
                "introduced": "0"
              },
              {
                "last_affected": "0.5.20"
              },
              {
                "fixed": "0.5.20"
              }
            ],
            "source": [
              "AFFECTED_FIELD",
              "DESCRIPTION"
            ]
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "94602c9c2b7cbdb8efd5c52802dac6a1c180089e"
            }
          ],
          "repo": "https://github.com/sgl-project/sglang",
          "type": "GIT"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "VulnCheck",
    "cwe_ids": [
      "CWE-770"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/93xxx/CVE-2026-93838.json"
  },
  "details": "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.",
  "id": "CVE-2026-93838",
  "modified": "2026-09-25T03:30:29.799159864Z",
  "published": "2026-09-18T19:06:03.899Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/93xxx/CVE-2026-93838.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-93838"
    },
    {
      "type": "ADVISORY",
      "url": "https://www.vulncheck.com/advisories/sglang-through-0.5.20-unbounded-memory-allocation-via-staging-req-chunk-idx"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/sgl-project/sglang/issues/39764"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/sgl-project/sglang"
    },
    {
      "type": "PACKAGE",
      "url": "https://pypi.org/project/sglang"
    },
    {
      "type": "ARTICLE",
      "url": "https://github.com/sgl-project/sglang/blob/v0.5.20/python/sglang/srt/disaggregation/common/conn.py#L1636-L1640"
    },
    {
      "type": "ARTICLE",
      "url": "https://github.com/sgl-project/sglang/blob/v0.5.20/python/sglang/srt/disaggregation/common/staging_handler.py#L781"
    },
    {
      "type": "ARTICLE",
      "url": "https://github.com/sgl-project/sglang/blob/v0.5.20/python/sglang/srt/disaggregation/common/staging_handler.py#L848-L860"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "SGLang through 0.5.20 Unbounded Memory Allocation via STAGING_REQ chunk_idx"
}