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PYSEC-2026-330

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

Impact

EPyT-Flow’s REST API parses attacker-controlled JSON request bodies using a custom deserializer (my_load_from_json) that supports a type field. When type is present, the deserializer dynamically imports an attacker-specified module/class and instantiates it with attacker-supplied arguments. This allows invoking dangerous classes such as subprocess.Popen, which can lead to OS command execution during JSON parsing. This also affects the loading of JSON files.

Patches

EPyT-Flow has been patched in 0.16.1 -- affects all versions <= 0.16.0

Workarounds

Do not load any JSON from untrusted sources and do not expose the REST API.

### Credits EPyT-Flow thanks Jarrett Chan (@syphonetic) for detecting and reporting the bug.

Severity
10.0 (Critical)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
Impacted products
Name purl
epyt-flow pkg:pypi/epyt-flow
Aliases
To clipboard 

{
  "affected": [
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "epyt-flow",
        "purl": "pkg:pypi/epyt-flow"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "0.16.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "0.1.0",
        "0.1.1",
        "0.10.0",
        "0.11.0",
        "0.12.0",
        "0.13.0",
        "0.13.1",
        "0.14.0",
        "0.14.1",
        "0.14.2",
        "0.15.0",
        "0.15.0b1",
        "0.16.0",
        "0.2.0",
        "0.3.0",
        "0.4.0",
        "0.5.0",
        "0.6.0",
        "0.7.0",
        "0.7.1",
        "0.7.2",
        "0.7.3",
        "0.8.0",
        "0.8.1",
        "0.9.0"
      ]
    }
  ],
  "aliases": [
    "CVE-2026-25632",
    "GHSA-74vm-8frp-7w68"
  ],
  "details": "### Impact\nEPyT-Flow\u2019s REST API parses attacker-controlled JSON request bodies using a custom deserializer (my_load_from_json) that supports a __type__ field. When __type__ is present, the deserializer dynamically imports an attacker-specified module/class and instantiates it with attacker-supplied arguments. This allows invoking dangerous classes such as subprocess.Popen, which can lead to OS command execution during JSON parsing. This also affects the loading of JSON files.\n\n### Patches\nEPyT-Flow  has been patched in 0.16.1 -- affects all versions \u003c= 0.16.0\n\n### Workarounds\n Do not load any JSON from untrusted sources and do not expose the REST API.\n\n ### Credits\nEPyT-Flow  thanks Jarrett Chan (@syphonetic) for detecting and reporting the bug.",
  "id": "PYSEC-2026-330",
  "modified": "2026-07-01T20:22:52.406443Z",
  "published": "2026-06-29T11:50:50.959788Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/WaterFutures/EPyT-Flow/security/advisories/GHSA-74vm-8frp-7w68"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-25632"
    },
    {
      "type": "WEB",
      "url": "https://github.com/WaterFutures/EPyT-Flow/commit/3fff9151494c7dbc72073830b734f0a7e550e385"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/WaterFutures/EPyT-Flow"
    },
    {
      "type": "WEB",
      "url": "https://github.com/WaterFutures/EPyT-Flow/releases/tag/v0.16.1"
    },
    {
      "type": "PACKAGE",
      "url": "https://pypi.org/project/epyt-flow"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/advisories/GHSA-74vm-8frp-7w68"
    }
  ],
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "EPyT-Flow vulnerable to unsafe JSON deserialization (__type__)"
}



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