GHSA-r8g5-cgf2-4m4m: Picklescan Picklescan Missing Detection When Calling Vulnerability

HIGH
Share
CWE-502
Published
Advisory Summary

GHSA-r8g5-cgf2-4m4m is a HIGH picklescan missing detection when calling vulnerability (CWE-502: Deserialization of Untrusted Data) affecting Picklescan libraries in the PyPI ecosystem. The issue involves picklescan missing detection when calling numpy.f2py.crackfortran.getlincoef. Remediation is available by upgrading affected packages to version 0.0.33.

GHSA-r8g5-cgf2-4m4m at a Glance

CVE Identifier N/A
GHSA Identifier GHSA-r8g5-cgf2-4m4m
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 GHSA-r8g5-cgf2-4m4m

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: 0.0.33 
pip install picklescan>=0.0.33
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 GHSA-r8g5-cgf2-4m4m, 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 0.0.33), 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 an attacker to execute arbitrary code on the host when loading a malicious pickle payload from an untrusted source. ### Details The `numpy.f2py.crackfortran` module exposes many functions that call `eval` on arbitrary strings of values. This is the case for `getlincoef` and `_eval_length`. This list is probably not exhaustive. According to https://numpy.org/doc/stable/reference/security.html#advice-for-using-numpy-on-untrusted-data, the whole `numpy.f2py` should be considered unsafe when loading a pickle. ### PoC ```python from numpy.f2py.crackfortran import getlincoef class EvilClass: def __reduce__(self): payload = "__import__('os').system('echo \"successful attack\"')" return getlincoef, (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 across ML models, APIs, or saved Python objects. ### Note The problem was originally reported to the joblib project, but this was deemed unrelated to joblib itself. However, I checked that `picklescan` was indeed vulnerable.

GHSA-r8g5-cgf2-4m4m Affected Picklescan Versions

1 component(s)
Fixed Versions:
0.0.33
Product / Package Ecosystem Affected Versions Fixed Version
picklescan
pypi/picklescan
PyPI
< 0.0.33
0.0.33

References

GitHub Advisory / Wiki ADVISORY
https://github.com/mmaitre314/picklescan/security/advisories/GHSA-r8g5-cgf2-4m4m
Picklescan Source Repository REPOSITORY
https://github.com/mmaitre314/picklescan/pull/53
Security Fix Commit FIX COMMIT
https://github.com/mmaitre314/picklescan/commit/70c1c6c31beb6baaf52c8db1b6c3c0e84a6f9dab
Picklescan Source Repository REPOSITORY
https://github.com/mmaitre314/picklescan
Picklescan Release RELEASE
https://github.com/mmaitre314/picklescan/releases/tag/v0.0.33

Frequently Asked Questions

What is GHSA-r8g5-cgf2-4m4m?
GHSA-r8g5-cgf2-4m4m is a security vulnerability in Picklescan involving Picklescan missing detection when calling numpy.f2py.crackfortran.getlincoef under CWE-502: Deserialization of Untrusted Data.
Which Picklescan versions are affected?
Affected versions include releases prior to 0.0.33 across affected packages: picklescan.
What version fixes GHSA-r8g5-cgf2-4m4m?
Upgrading to 0.0.33 (or the latest patched release for your respective branch) resolves the vulnerability.
Is picklescan affected?
Yes, picklescan is affected in releases prior to 0.0.33. Upgrade your dependency to 0.0.33 or later.
What CWE is associated with GHSA-r8g5-cgf2-4m4m?
GHSA-r8g5-cgf2-4m4m 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 GHSA-r8g5-cgf2-4m4m?
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-r8g5-cgf2-4m4m",
  "modified" : "2025-12-29T15:27:59Z",
  "published" : "2025-12-29T15:27:59Z",
  "aliases" : [ ],
  "summary" : "Picklescan missing detection when calling numpy.f2py.crackfortran.getlincoef",
  "details" : "### Summary\n\nAn unsafe deserialization vulnerability allows an attacker to execute arbitrary code on the host when loading a malicious pickle payload from an untrusted source.\n\n### Details\n\nThe `numpy.f2py.crackfortran` module exposes many functions that call `eval` on arbitrary strings of values. This is the case for `getlincoef` and `_eval_length`. This list is probably not exhaustive.\n\nAccording to https://numpy.org/doc/stable/reference/security.html#advice-for-using-numpy-on-untrusted-data, the whole `numpy.f2py` should be considered unsafe when loading a pickle.\n\n### PoC\n\n```python\nfrom numpy.f2py.crackfortran import getlincoef\n\nclass EvilClass:\n    def __reduce__(self):\n        payload = \"__import__('os').system('echo \\\"successful attack\\\"')\"\n        return getlincoef, (payload, [])\n```\n\n### Impact\n\nWho is impacted? Any organization or individual relying on `picklescan` to detect malicious pickle files from untrusted sources.\nWhat is the impact? Attackers can embed malicious code in pickle file that remains undetected but executes when the pickle file is loaded.\nSupply Chain Attack: Attackers can distribute infected pickle files across ML models, APIs, or saved Python objects.\n\n### Note\n\nThe problem was originally reported to the joblib project, but this was deemed unrelated to joblib itself. However, I checked that `picklescan` was indeed vulnerable.",
  "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" : "0.0.33"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/mmaitre314/picklescan/security/advisories/GHSA-r8g5-cgf2-4m4m"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/mmaitre314/picklescan/pull/53"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/mmaitre314/picklescan/commit/70c1c6c31beb6baaf52c8db1b6c3c0e84a6f9dab"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/mmaitre314/picklescan"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/mmaitre314/picklescan/releases/tag/v0.0.33"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-502" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2025-12-29T15:27:59Z",
    "nvd_published_at" : null
  }
}