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PYSEC-2026-350

Vulnerability from pysec - Published: 2026-06-29 11:50 - Updated: 2026-07-01 20:22
VLAI
Details

Remote unauthenticated attackers can overwrite arbitrary server files with attacker-controllable data. The data that the attacker can control is not entirely arbitrary. h2o writes a CSV/XLS/etc file to disk, so the attacker data is wrapped in quotations and starts with "C1", if they're exporting as CSV.

Severity
9.3 (Critical)
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:H
Impacted products
Name purl
h2o pkg:pypi/h2o
Aliases
To clipboard 

{
  "affected": [
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "h2o",
        "purl": "pkg:pypi/h2o"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3.46.0.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "3.10.0.10",
        "3.10.0.3",
        "3.10.0.6",
        "3.10.0.7",
        "3.10.0.8",
        "3.10.3.3",
        "3.10.3.4",
        "3.10.4.1",
        "3.10.4.2",
        "3.10.4.3",
        "3.10.4.4",
        "3.10.4.6",
        "3.10.4.8",
        "3.16.0.1",
        "3.16.0.2",
        "3.16.0.3",
        "3.16.0.4",
        "3.18.0.1",
        "3.18.0.10",
        "3.18.0.11",
        "3.18.0.2",
        "3.18.0.3",
        "3.18.0.4",
        "3.18.0.5",
        "3.18.0.6",
        "3.18.0.7",
        "3.18.0.8",
        "3.18.0.9",
        "3.20.0.4",
        "3.20.0.5",
        "3.20.0.6",
        "3.20.0.7",
        "3.20.0.8",
        "3.22.0.1",
        "3.22.0.2",
        "3.22.0.3",
        "3.22.0.4",
        "3.22.0.5",
        "3.22.1.1",
        "3.22.1.2",
        "3.22.1.3",
        "3.22.1.4",
        "3.22.1.5",
        "3.22.1.6",
        "3.24.0.1",
        "3.24.0.2",
        "3.24.0.3",
        "3.24.0.4",
        "3.24.0.5",
        "3.26.0.1",
        "3.26.0.10",
        "3.26.0.11",
        "3.26.0.2",
        "3.26.0.3",
        "3.26.0.4",
        "3.26.0.5",
        "3.26.0.6",
        "3.26.0.8",
        "3.26.0.9",
        "3.28.0.1",
        "3.28.0.2",
        "3.28.0.3",
        "3.28.1.2",
        "3.28.1.3",
        "3.30.0.1",
        "3.30.0.2",
        "3.30.0.3",
        "3.30.0.4",
        "3.30.0.5",
        "3.30.0.6",
        "3.30.0.7",
        "3.30.1.1",
        "3.30.1.2",
        "3.30.1.3",
        "3.32.0.2",
        "3.32.0.3",
        "3.32.0.4",
        "3.32.0.5",
        "3.32.1.1",
        "3.32.1.2",
        "3.32.1.3",
        "3.32.1.4",
        "3.32.1.5",
        "3.32.1.6",
        "3.32.1.7",
        "3.34.0.3",
        "3.34.0.7",
        "3.34.0.8",
        "3.36.0.2",
        "3.36.0.3",
        "3.36.0.4",
        "3.36.1.1",
        "3.36.1.2",
        "3.36.1.3",
        "3.36.1.4",
        "3.36.1.5",
        "3.38.0.1",
        "3.38.0.2",
        "3.38.0.3",
        "3.38.0.4",
        "3.40.0.1",
        "3.40.0.2",
        "3.40.0.3",
        "3.40.0.4",
        "3.42.0.1",
        "3.42.0.2",
        "3.42.0.3",
        "3.42.0.4",
        "3.44.0.1",
        "3.44.0.2",
        "3.44.0.3"
      ]
    }
  ],
  "aliases": [
    "CVE-2023-6569",
    "GHSA-gqrq-j6pm-98c2"
  ],
  "details": "Remote unauthenticated attackers can overwrite arbitrary server files with attacker-controllable data. The data that the attacker can control is not entirely arbitrary. h2o writes a CSV/XLS/etc file to disk, so the attacker data is wrapped in quotations and starts with \"C1\", if they\u0027re exporting as CSV.",
  "id": "PYSEC-2026-350",
  "modified": "2026-07-01T20:22:54.105066Z",
  "published": "2026-06-29T11:50:44.448598Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2023-6569"
    },
    {
      "type": "WEB",
      "url": "https://github.com/h2oai/h2o-3/commit/e8884f5187eb81311877c5f0dd4d6d9c70f33d78"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/h2oai/h2o-3"
    },
    {
      "type": "WEB",
      "url": "https://huntr.com/bounties/a5d003dc-c23e-4c98-8dcf-35ba9252fa3c"
    },
    {
      "type": "PACKAGE",
      "url": "https://pypi.org/project/h2o"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/advisories/GHSA-gqrq-j6pm-98c2"
    }
  ],
  "severity": [
    {
      "score": "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "External Control of File Name or Path in h2oai/h2o-3"
}



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