Vulnerability-Lookup

PYSEC-2026-27

Vulnerability from pysec - Published: 2026-03-26 17:16 - Updated: 2026-05-20 09:18

Details

Briefcase is a tool for converting a Python project into a standalone native application. Starting in version 0.3.0 and prior to version 0.3.26, if a developer uses Briefcase to produce an Windows MSI installer for a project, and that project is installed for All Users (i.e., per-machine scope), the installation process creates an directory that inherits all the permissions of the parent directory. Depending on the location chosen by the installing user, this may allow a low privilege but authenticated user to replace or modify the binaries installed by the application. If an administrator then runs the altered binary, the binary will run with elevated privileges. The problem is caused by the template used to generate the WXS file for Windows projects. It was fixed in the templates used in Briefcase 0.3.26, 0.4.0, and 0.4.1. Re-running briefcase create on your Briefcase project will result in the updated templates being used. As a workaround, the patch can be added to any existing Briefcase .wxs file generated by Briefcase 0.3.24 or later.

Severity

7.3 (High)


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

Impacted products

Name	purl
briefcase	pkg:pypi/briefcase

Aliases

JSON

To clipboard

{
  "affected": [
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "briefcase",
        "purl": "pkg:pypi/briefcase"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0.3.0"
            },
            {
              "fixed": "0.3.26"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "0.3.0",
        "0.3.1",
        "0.3.10",
        "0.3.10rc7",
        "0.3.10rc8",
        "0.3.11",
        "0.3.11rc4",
        "0.3.12",
        "0.3.13",
        "0.3.14",
        "0.3.15",
        "0.3.16",
        "0.3.17",
        "0.3.18",
        "0.3.19",
        "0.3.2",
        "0.3.20",
        "0.3.21",
        "0.3.22",
        "0.3.23",
        "0.3.24",
        "0.3.25",
        "0.3.26rc5",
        "0.3.3",
        "0.3.4",
        "0.3.5",
        "0.3.6",
        "0.3.7",
        "0.3.8",
        "0.3.9"
      ]
    }
  ],
  "aliases": [
    "CVE-2026-33430",
    "GHSA-r3r2-35v9-v238"
  ],
  "details": "Briefcase is a tool for converting a Python project into a standalone native application. Starting in version 0.3.0 and prior to version 0.3.26, if a developer uses Briefcase to produce an Windows MSI installer for a project, and that project is installed for All Users (i.e., per-machine scope), the installation process creates an directory that inherits all the permissions of the parent directory. Depending on the location chosen by the installing user, this may allow a low privilege but authenticated user to replace or modify the binaries installed by the application. If an administrator then runs the altered binary, the binary will run with elevated privileges. The problem is caused by the template used to generate the WXS file for Windows projects. It was fixed in the templates used in Briefcase 0.3.26, 0.4.0, and 0.4.1. Re-running `briefcase create` on your Briefcase project will result in the updated templates being used. As a workaround, the patch can be added to any existing Briefcase .wxs file generated by Briefcase 0.3.24 or later.",
  "id": "PYSEC-2026-27",
  "modified": "2026-05-20T09:18:53.838122Z",
  "published": "2026-03-26T17:16:38.713Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://github.com/beeware/briefcase/issues/2759"
    },
    {
      "type": "FIX",
      "url": "https://github.com/beeware/briefcase-windows-VisualStudio-template/pull/85"
    },
    {
      "type": "FIX",
      "url": "https://github.com/beeware/briefcase-windows-app-template/pull/86"
    },
    {
      "type": "FIX",
      "url": "https://github.com/beeware/briefcase/security/advisories/GHSA-r3r2-35v9-v238"
    }
  ],
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-33430 (GCVE-0-2026-33430)

Vulnerability from cvelistv5 – Published: 2026-03-26 16:54 – Updated: 2026-04-01 03:55

Title

Briefcase: Windows MSI Installer Privilege Escalation via Insecure Directory Permissions

Summary

Briefcase is a tool for converting a Python project into a standalone native application. Starting in version 0.3.0 and prior to version 0.3.26, if a developer uses Briefcase to produce an Windows MSI installer for a project, and that project is installed for All Users (i.e., per-machine scope), the installation process creates an directory that inherits all the permissions of the parent directory. Depending on the location chosen by the installing user, this may allow a low privilege but authenticated user to replace or modify the binaries installed by the application. If an administrator then runs the altered binary, the binary will run with elevated privileges. The problem is caused by the template used to generate the WXS file for Windows projects. It was fixed in the templates used in Briefcase 0.3.26, 0.4.0, and 0.4.1. Re-running `briefcase create` on your Briefcase project will result in the updated templates being used. As a workaround, the patch can be added to any existing Briefcase .wxs file generated by Briefcase 0.3.24 or later.

Severity

7.3 (High)


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

SSVC

Exploitation: none Automatable: no Technical Impact: total

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-03-31 00:00 UTC

CWE

CWE-732 - Incorrect Permission Assignment for Critical Resource

Assigner

GitHub_M

References

4 references

URL	Tags
https://github.com/beeware/briefcase/security/adv…	x_refsource_CONFIRM
https://github.com/beeware/briefcase/issues/2759	x_refsource_MISC
https://github.com/beeware/briefcase-windows-Visu…	x_refsource_MISC
https://github.com/beeware/briefcase-windows-app-…	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
beeware	briefcase	Affected: >= 0.3.0, < 0.3.26

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-33430",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-03-31T00:00:00+00:00",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-04-01T03:55:18.727Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "briefcase",
          "vendor": "beeware",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= 0.3.0, \u003c 0.3.26"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Briefcase is a tool for converting a Python project into a standalone native application. Starting in version 0.3.0 and prior to version 0.3.26, if a developer uses Briefcase to produce an Windows MSI installer for a project, and that project is installed for All Users (i.e., per-machine scope), the installation process creates an directory that inherits all the permissions of the parent directory. Depending on the location chosen by the installing user, this may allow a low privilege but authenticated user to replace or modify the binaries installed by the application. If an administrator then runs the altered binary, the binary will run with elevated privileges. The problem is caused by the template used to generate the WXS file for Windows projects. It was fixed in the templates used in Briefcase 0.3.26, 0.4.0, and 0.4.1. Re-running `briefcase create` on your Briefcase project will result in the updated templates being used. As a workaround, the patch can be added to any existing Briefcase .wxs file generated by Briefcase 0.3.24 or later."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "LOCAL",
            "availabilityImpact": "HIGH",
            "baseScore": 7.3,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "HIGH",
            "privilegesRequired": "LOW",
            "scope": "UNCHANGED",
            "userInteraction": "REQUIRED",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-732",
              "description": "CWE-732: Incorrect Permission Assignment for Critical Resource",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-03-26T16:54:42.992Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/beeware/briefcase/security/advisories/GHSA-r3r2-35v9-v238",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/beeware/briefcase/security/advisories/GHSA-r3r2-35v9-v238"
        },
        {
          "name": "https://github.com/beeware/briefcase/issues/2759",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/beeware/briefcase/issues/2759"
        },
        {
          "name": "https://github.com/beeware/briefcase-windows-VisualStudio-template/pull/85",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/beeware/briefcase-windows-VisualStudio-template/pull/85"
        },
        {
          "name": "https://github.com/beeware/briefcase-windows-app-template/pull/86",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/beeware/briefcase-windows-app-template/pull/86"
        }
      ],
      "source": {
        "advisory": "GHSA-r3r2-35v9-v238",
        "discovery": "UNKNOWN"
      },
      "title": "Briefcase: Windows MSI Installer Privilege Escalation via Insecure Directory Permissions"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-33430",
    "datePublished": "2026-03-26T16:54:42.992Z",
    "dateReserved": "2026-03-19T18:45:22.435Z",
    "dateUpdated": "2026-04-01T03:55:18.727Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

GHSA-R3R2-35V9-V238

Vulnerability from github – Published: 2026-03-23 21:40 – Updated: 2026-06-05 14:26

Summary

Briefcase: Windows MSI Installer Privilege Escalation via Insecure Directory Permissions

Details

Impact

If a developer uses Briefcase to produce an Windows MSI installer for a project, and that project is installed for All Users (i.e., per-machine scope), the installation process creates an directory that inherits all the permissions of the parent directory. Depending on the location chosen by the installing user, this may allow a low privilege but authenticated user to replace or modify the binaries installed by the application. If an administrator then runs the altered binary, the binary will run with elevated privileges.

Patches

The problem is caused by the template used to generate the WXS file for Windows projects. It was fixed with the following PRs:

beeware/briefcase-windows-app-template#86
beeware/briefcase-windows-VisualStudio-template#85

These patches have been backported to the templates used in Briefcase 0.3.26, 0.4.0, and 0.4.1. Re-running briefcase create on your Briefcase project will result in the updated templates being used.

Workarounds

The change from beeware/briefcase-windows-app-template#86 can be added to any existing Briefcase .wxs file generated by Briefcase 0.3.24 or later.

Resources

beeware/briefcase#2759 is a formal bug report of the problem.

Severity

7.3 (High)


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

Show details on source website

JSON

To clipboard

{
  "affected": [
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "briefcase"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0.3.0"
            },
            {
              "fixed": "0.3.26"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-33430"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-732"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-03-23T21:40:10Z",
    "nvd_published_at": "2026-03-26T17:16:38Z",
    "severity": "HIGH"
  },
  "details": "### Impact\n\nIf a developer uses Briefcase to produce an Windows MSI installer for a project, and that project is installed for All Users (i.e., per-machine scope), the installation process creates an directory that inherits all the permissions of the parent directory. Depending on the location chosen by the installing user, this may allow a low privilege but authenticated user to replace or modify the binaries installed by the application. If an administrator then runs the altered binary, the binary will run with elevated privileges.\n\n### Patches\n\nThe problem is caused by the template used to generate the WXS file for Windows projects. It was fixed with the following PRs:\n\n* beeware/briefcase-windows-app-template#86\n* beeware/briefcase-windows-VisualStudio-template#85\n\nThese patches have been backported to the templates used in Briefcase 0.3.26, 0.4.0, and 0.4.1. Re-running `briefcase create` on your Briefcase project will result in the updated templates being used.\n\n### Workarounds\n\nThe change from beeware/briefcase-windows-app-template#86 can be added to any existing Briefcase .wxs file generated by Briefcase 0.3.24 or later.\n\n### Resources\n\nbeeware/briefcase#2759 is a formal bug report of the problem.",
  "id": "GHSA-r3r2-35v9-v238",
  "modified": "2026-06-05T14:26:48Z",
  "published": "2026-03-23T21:40:10Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/beeware/briefcase/security/advisories/GHSA-r3r2-35v9-v238"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-33430"
    },
    {
      "type": "WEB",
      "url": "https://github.com/beeware/briefcase/issues/2759"
    },
    {
      "type": "WEB",
      "url": "https://github.com/beeware/briefcase-windows-VisualStudio-template/pull/85"
    },
    {
      "type": "WEB",
      "url": "https://github.com/beeware/briefcase-windows-app-template/pull/86"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/beeware/briefcase"
    },
    {
      "type": "WEB",
      "url": "https://github.com/pypa/advisory-database/tree/main/vulns/briefcase/PYSEC-2026-27.yaml"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Briefcase: Windows MSI Installer Privilege Escalation via Insecure Directory Permissions "
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
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.

Detection rules are retrieved from Rulezet.

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.

Action not permitted

PYSEC-2026-27

CVE-2026-33430 (GCVE-0-2026-33430)

GHSA-R3R2-35V9-V238

Impact

Patches

Workarounds

Resources

Tags

Sightings

Nomenclature