CVE-2026-53874: Picklescan Picklescan Missing Detection By Simple Vulnerability

HIGH
Advisory Identifier: GHSA-9m3x-qqw2-h32h
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CWE-502
Published
Advisory Summary

CVE-2026-53874 is a HIGH picklescan missing detection by simple vulnerability (CWE-502: Deserialization of Untrusted Data) affecting Picklescan libraries in the PyPI ecosystem. The issue involves picklescan missing detection by simple obfuscation of a `builtins.eval` call. Remediation is available by upgrading affected packages to version 1.0.1.

CVE-2026-53874 at a Glance

CVE Identifier CVE-2026-53874
GHSA Identifier GHSA-9m3x-qqw2-h32h
Severity HIGH
CVSS v3.1 Base Score N/A
CWE Classification CWE-502: Deserialization of Untrusted Data
Affected Product Picklescan
Package Ecosystem PyPI
Published Date
Last Updated

How to Fix CVE-2026-53874

To remediate this vulnerability, upgrade all affected Picklescan dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

picklescan fixed: 1.0.1 
pip install picklescan>=1.0.1
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

pip show picklescan

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2026-53874, inspect your installed packages using pip:

pip show picklescan

Analyze the terminal output to locate any version of Picklescan in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.0.1), your application is affected.

Note: The pip show picklescan command checks currently installed packages in your active Python environment.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-502: Deserialization of Untrusted Data, where the product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid. In Picklescan, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

### Summary An unsafe deserialization vulnerability allows any unauthenticated user to execute arbitrary code on the host loading a pickle payload from an untrusted source. ### Details It's possible to hide the `eval` call nested under another callable via `getattr`. ### PoC ```python import builtins class EvilClass: @staticmethod def _obfuscated_eval(payload): getattr(builtins, "eval")(payload) def __reduce__(self): payload = "__import__('os').system('echo \"successful attack\"')" return self._obfuscated_eval, (payload,) ``` ### Impact Who is impacted? Any organization or individual relying on picklescan to detect malicious pickle files from untrusted sources. What is the impact? Attackers can embed malicious code in pickle file that remains undetected but executes when the pickle file is loaded. Supply Chain Attack: Attackers can distribute infected pickle files to system that load serialized ML models, APIs, or saved Python objects from untrusted sources.

CVE-2026-53874 Affected Picklescan Versions

1 component(s)
Fixed Versions:
1.0.1
Product / Package Ecosystem Affected Versions Fixed Version
picklescan
pypi/picklescan
PyPI
< 1.0.1
1.0.1

References

GitHub Advisory / Wiki ADVISORY
https://github.com/mmaitre314/picklescan/security/advisories/GHSA-9m3x-qqw2-h32h
NVD — CVE-2026-53874 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-53874
Picklescan Source Repository REPOSITORY
https://github.com/mmaitre314/picklescan/pull/59
Security Fix Commit FIX COMMIT
https://github.com/mmaitre314/picklescan/commit/173c8f2a869ea9b69b543477525ec70611c3c6f4
Picklescan Source Repository REPOSITORY
https://github.com/mmaitre314/picklescan
Picklescan Release RELEASE
https://github.com/mmaitre314/picklescan/releases/tag/v1.0.1
www.vulncheck.com/advisories/picklesc... WEB
https://www.vulncheck.com/advisories/picklescan-arbitrary-code-execution-via-obfuscated-eval-call

Frequently Asked Questions

What is CVE-2026-53874?
CVE-2026-53874 is a security vulnerability in Picklescan involving picklescan missing detection by simple obfuscation of a `builtins.eval` call under CWE-502: Deserialization of Untrusted Data.
Which Picklescan versions are affected?
Affected versions include releases prior to 1.0.1 across affected packages: picklescan.
What version fixes CVE-2026-53874?
Upgrading to 1.0.1 (or the latest patched release for your respective branch) resolves the vulnerability.
Is picklescan affected?
Yes, picklescan is affected in releases prior to 1.0.1. Upgrade your dependency to 1.0.1 or later.
What CWE is associated with CVE-2026-53874?
CVE-2026-53874 is classified under CWE-502: Deserialization of Untrusted Data (The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.).
How can I check PyPI dependencies for CVE-2026-53874?
Run the dependency tree command: 'pip show picklescan'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-9m3x-qqw2-h32h",
  "modified" : "2026-06-18T14:41:54Z",
  "published" : "2026-02-02T20:45:20Z",
  "aliases" : [ "CVE-2026-53874" ],
  "summary" : "picklescan missing detection by simple obfuscation of a `builtins.eval` call",
  "details" : "### Summary\n\nAn unsafe deserialization vulnerability allows any unauthenticated user to execute arbitrary code on the host loading a pickle payload from an untrusted source.\n\n### Details\n\nIt's possible to hide the `eval` call nested under another callable via `getattr`.\n\n### PoC\n\n```python\nimport builtins\n\nclass EvilClass:\n    @staticmethod\n    def _obfuscated_eval(payload):\n        getattr(builtins, \"eval\")(payload)\n\n    def __reduce__(self):\n        payload = \"__import__('os').system('echo \\\"successful attack\\\"')\"\n        return self._obfuscated_eval, (payload,)\n```\n\n\n### Impact\n\nWho is impacted? \nAny organization or individual relying on picklescan to detect malicious pickle files from untrusted sources.\n\nWhat is the impact? \nAttackers can embed malicious code in pickle file that remains undetected but executes when the pickle file is loaded.\n\nSupply Chain Attack: Attackers can distribute infected pickle files to system that load serialized ML models, APIs, or saved Python objects from untrusted sources.",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "picklescan"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.0.1"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/mmaitre314/picklescan/security/advisories/GHSA-9m3x-qqw2-h32h"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-53874"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/mmaitre314/picklescan/pull/59"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/mmaitre314/picklescan/commit/173c8f2a869ea9b69b543477525ec70611c3c6f4"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/mmaitre314/picklescan"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/mmaitre314/picklescan/releases/tag/v1.0.1"
  }, {
    "type" : "WEB",
    "url" : "https://www.vulncheck.com/advisories/picklescan-arbitrary-code-execution-via-obfuscated-eval-call"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-502" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-02-02T20:45:20Z",
    "nvd_published_at" : null
  }
}