PYSEC-2026-282

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

The JSONSerializer and CBORSerializer in APScheduler (all versions including 3.10.x and 4.0.0a5) are vulnerable to Remote Code Execution (RCE) via Insecure Deserialization. The unmarshal_object function allows for arbitrary class instantiation and state injection by dynamically importing modules and calling setstate on any class available in the Python environment. An attacker can exploit this by submitting a specially crafted JSON or CBOR payload to an application using these serializers

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

{
  "affected": [
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "apscheduler",
        "purl": "pkg:pypi/apscheduler"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "4.0.0a1"
            },
            {
              "last_affected": "4.0.0a6"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "4.0.0a1",
        "4.0.0a2",
        "4.0.0a3",
        "4.0.0a4",
        "4.0.0a5",
        "4.0.0a6"
      ]
    }
  ],
  "aliases": [
    "CVE-2026-31072",
    "GHSA-9cfw-f3f9-7mm7"
  ],
  "details": "The JSONSerializer and CBORSerializer in APScheduler (all versions including 3.10.x and 4.0.0a5) are vulnerable to Remote Code Execution (RCE) via Insecure Deserialization. The unmarshal_object function allows for arbitrary class instantiation and state injection by dynamically importing modules and calling __setstate__ on any class available in the Python environment. An attacker can exploit this by submitting a specially crafted JSON or CBOR payload to an application using these serializers",
  "id": "PYSEC-2026-282",
  "modified": "2026-07-01T20:22:49.421836Z",
  "published": "2026-06-29T11:50:49.946441Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-31072"
    },
    {
      "type": "WEB",
      "url": "https://gist.github.com/nedlir/11fb77f35a59cbba73392a086b02a9c6"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/agronholm/apscheduler"
    },
    {
      "type": "PACKAGE",
      "url": "https://pypi.org/project/apscheduler"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/advisories/GHSA-9cfw-f3f9-7mm7"
    }
  ],
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "APScheduler\u0027s JSONSerializer and CBORSerializer are vulnerable to Remote Code Execution (RCE) via Insecure Deserialization"
}



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