Common Weakness Enumeration

CWE-1066

Weakness Prohibited

Missing Serialization Control Element

Abstraction: Base · Status: Incomplete

The product contains a serializable data element that does not have an associated serialization method.

Mapping guidance

This entry is primarily a quality issue with no direct security implications.

Look for weaknesses that are focused specifically on insecure behaviors that have more direct security implications.

Relationships and members
ChildOf: CWE-710 · View CWE-1000
Modes of introduction
Implementation
Detection methods

Automated Static Analysis

Automated static analysis, commonly referred to as Static Application Security Testing (SAST), can find some instances of this weakness by analyzing source code (or binary/compiled code) without having to execute it. Typically, this is done by building a model of data flow and control flow, then searching for potentially-vulnerable patterns that connect "sources" (origins of input) with "sinks" (destinations where the data interacts with external components, a lower layer such as the OS, etc.)

Effectiveness: High

Content history
Submission: CWE Content Team · MITRE · 2018-07-02 · CWE 3.2

Entry derived from Common Quality Enumeration (CQE) Draft 0.9.

Modification: CWE Content Team · MITRE · 2020-02-24 · CWE 4.0

updated Description

Modification: CWE Content Team · MITRE · 2020-08-20 · CWE 4.2

updated Relationships

Modification: CWE Content Team · MITRE · 2023-01-31 · CWE 4.10

updated Description

Modification: CWE Content Team · MITRE · 2023-04-27 · CWE 4.11

updated Relationships

Modification: CWE Content Team · MITRE · 2023-06-29 · CWE 4.12

updated Mapping_Notes

Modification: CWE Content Team · MITRE · 2024-02-29 · CWE 4.14

updated Mapping_Notes

Modification: CWE Content Team · MITRE · 2025-12-11 · CWE 4.19

updated Applicable_Platforms, Background_Details, Common_Consequences, Description, Time_of_Introduction

Modification: CWE Content Team · MITRE · 2026-10-28 · CWE 5.0

updated Detection_Factors, References

2 vulnerabilities reference this CWE, most recent first.

CVE-2026-4372 (GCVE-0-2026-4372)

Vulnerability from cvelistv5 – Published: 2026-05-24 13:40 – Updated: 2026-05-26 15:21
VLAI
Title
Arbitrary Remote Code Execution via `_attn_implementation_internal` Config Injection in huggingface/transformers
Summary
A critical remote code execution vulnerability exists in all versions of the HuggingFace transformers library prior to version 5.3.0. The vulnerability allows an attacker to craft a malicious `config.json` file containing the `_attn_implementation_internal` field set to an attacker-controlled HuggingFace Hub repository ID. When a victim loads this model using the standard `AutoModelForCausalLM.from_pretrained()` API, the library downloads and executes arbitrary Python code from the attacker's repository with the victim's full OS privileges. This issue arises due to unfiltered deserialization of configuration attributes, insufficient sanitization of internal fields, and unsandboxed execution of downloaded kernels. The vulnerability bypasses the `trust_remote_code` security mechanism, is invisible to the victim, and exploits the standard documented usage pattern, making it particularly severe. Users are advised to upgrade to version 5.3.0 or later to mitigate this issue.
SSVC
Exploitation: none Automatable: no Technical Impact: total
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-05-26 15:08 UTC
CWE
  • CWE-1066 - Missing Serialization Control Element
Assigner
@huntr_ai CNA under the mitre root
CNA scorecard C 65/100 over 40 records in the last 180 days details
Impacted products
Vendor Product Version
huggingface huggingface/transformers Affected: unspecified , < 5.3.0 (custom)
Create a notification for this product.
Show details on NVD website

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-4372",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-05-26T15:08:29.632933Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-05-26T15:21:02.376Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "huggingface/transformers",
          "vendor": "huggingface",
          "versions": [
            {
              "lessThan": "5.3.0",
              "status": "affected",
              "version": "unspecified",
              "versionType": "custom"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "A critical remote code execution vulnerability exists in all versions of the HuggingFace transformers library prior to version 5.3.0. The vulnerability allows an attacker to craft a malicious `config.json` file containing the `_attn_implementation_internal` field set to an attacker-controlled HuggingFace Hub repository ID. When a victim loads this model using the standard `AutoModelForCausalLM.from_pretrained()` API, the library downloads and executes arbitrary Python code from the attacker\u0027s repository with the victim\u0027s full OS privileges. This issue arises due to unfiltered deserialization of configuration attributes, insufficient sanitization of internal fields, and unsandboxed execution of downloaded kernels. The vulnerability bypasses the `trust_remote_code` security mechanism, is invisible to the victim, and exploits the standard documented usage pattern, making it particularly severe. Users are advised to upgrade to version 5.3.0 or later to mitigate this issue."
        }
      ],
      "metrics": [
        {
          "cvssV3_0": {
            "attackComplexity": "LOW",
            "attackVector": "LOCAL",
            "availabilityImpact": "HIGH",
            "baseScore": 7.8,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "HIGH",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "REQUIRED",
            "vectorString": "CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H",
            "version": "3.0"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-1066",
              "description": "CWE-1066 Missing Serialization Control Element",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-05-24T13:40:40.995Z",
        "orgId": "c09c270a-b464-47c1-9133-acb35b22c19a",
        "shortName": "@huntr_ai"
      },
      "references": [
        {
          "url": "https://huntr.com/bounties/1f693a6e-6836-4b8b-a0bd-ca036fba8884"
        },
        {
          "url": "https://github.com/huggingface/transformers/commit/a7f8e7ff37d87d1a1a0c8cf607971c607741452f"
        }
      ],
      "source": {
        "advisory": "1f693a6e-6836-4b8b-a0bd-ca036fba8884",
        "discovery": "EXTERNAL"
      },
      "title": "Arbitrary Remote Code Execution via `_attn_implementation_internal` Config Injection in huggingface/transformers"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "c09c270a-b464-47c1-9133-acb35b22c19a",
    "assignerShortName": "@huntr_ai",
    "cveId": "CVE-2026-4372",
    "datePublished": "2026-05-24T13:40:40.995Z",
    "dateReserved": "2026-03-18T10:04:09.683Z",
    "dateUpdated": "2026-05-26T15:21:02.376Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

GHSA-29PF-2H5F-8G72

Vulnerability from github – Published: 2026-05-26 13:30 – Updated: 2026-07-01 18:00
VLAI
Summary
HuggingFace transformers vulnerable to remote code execution
Details

A critical remote code execution vulnerability exists in all versions of the HuggingFace transformers library prior to version 5.3.0. The vulnerability allows an attacker to craft a malicious config.json file containing the _attn_implementation_internal field set to an attacker-controlled HuggingFace Hub repository ID. When a victim loads this model using the standard AutoModelForCausalLM.from_pretrained() API, the library downloads and executes arbitrary Python code from the attacker's repository with the victim's full OS privileges. This issue arises due to unfiltered deserialization of configuration attributes, insufficient sanitization of internal fields, and unsandboxed execution of downloaded kernels. The vulnerability bypasses the trust_remote_code security mechanism, is invisible to the victim, and exploits the standard documented usage pattern, making it particularly severe. Users are advised to upgrade to version 5.3.0 or later to mitigate this issue.

Show details on source website

{
  "affected": [
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "transformers"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "5.3.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-4372"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-1066",
      "CWE-502"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-07-01T18:00:10Z",
    "nvd_published_at": "2026-05-24T14:16:16Z",
    "severity": "HIGH"
  },
  "details": "A critical remote code execution vulnerability exists in all versions of the HuggingFace transformers library prior to version 5.3.0. The vulnerability allows an attacker to craft a malicious `config.json` file containing the `_attn_implementation_internal` field set to an attacker-controlled HuggingFace Hub repository ID. When a victim loads this model using the standard `AutoModelForCausalLM.from_pretrained()` API, the library downloads and executes arbitrary Python code from the attacker\u0027s repository with the victim\u0027s full OS privileges. This issue arises due to unfiltered deserialization of configuration attributes, insufficient sanitization of internal fields, and unsandboxed execution of downloaded kernels. The vulnerability bypasses the `trust_remote_code` security mechanism, is invisible to the victim, and exploits the standard documented usage pattern, making it particularly severe. Users are advised to upgrade to version 5.3.0 or later to mitigate this issue.",
  "id": "GHSA-29pf-2h5f-8g72",
  "modified": "2026-07-01T18:00:10Z",
  "published": "2026-05-26T13:30:33Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-4372"
    },
    {
      "type": "WEB",
      "url": "https://github.com/huggingface/transformers/commit/a7f8e7ff37d87d1a1a0c8cf607971c607741452f"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/huggingface/transformers"
    },
    {
      "type": "WEB",
      "url": "https://huntr.com/bounties/1f693a6e-6836-4b8b-a0bd-ca036fba8884"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "HuggingFace transformers vulnerable to remote code execution"
}

No mitigation information available for this CWE.

No CAPEC attack patterns related to this CWE.