CVE-2026-40162: Bugsink Bugsink Affected By Authenticated Arbitrary Vulnerability

HIGH
Advisory Identifier: GHSA-8hw4-fhww-273g
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CVSS 7.1
CWE-20
Published
Advisory Summary

CVE-2026-40162 is a HIGH (CVSS 7.1) bugsink affected by authenticated arbitrary vulnerability (CWE-20: Improper Input Validation) affecting Bugsink libraries in the PyPI ecosystem. The issue involves bugsink affected by authenticated arbitrary file write in artifactbundle/assemble. Remediation is available by upgrading affected packages to version 2.1.1.

CVE-2026-40162 at a Glance

CVE Identifier CVE-2026-40162
GHSA Identifier GHSA-8hw4-fhww-273g
Severity HIGH
CVSS v3.1 Base Score 7.1
CWE Classification CWE-20: Improper Input Validation
Affected Product Bugsink
Package Ecosystem PyPI
Published Date
Last Updated

Security Impact

CVSS: 7.1

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:L).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required Low (PR:L)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality None (C:N)
Integrity High (I:H)
Availability Low (A:L)

How to Fix CVE-2026-40162

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

bugsink fixed: 2.1.1 
pip install bugsink>=2.1.1
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 bugsink

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2026-40162, inspect your installed packages using pip:

pip show bugsink

Analyze the terminal output to locate any version of Bugsink in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 2.1.1), your application is affected.

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

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-20: Improper Input Validation, where the product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly. In Bugsink, 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

# Authenticated arbitrary file write in artifact bundle assembly ## Summary An authenticated file write vulnerability was identified in Bugsink **2.1.0** in the artifact bundle assembly flow. A user with a valid authentication token could cause the application to write attacker-controlled content to a filesystem location writable by the Bugsink process. This issue requires authentication and affects only version **2.1.0**. The issue is fixed in **2.1.1**. ## Impact This vulnerability allows an authenticated user to create or overwrite files **within locations writable by the Bugsink service account**. The practical impact depends on the deployment environment and filesystem permissions of the running process. Possible consequences include: * modification of application data files * corruption of uploaded assets or temporary files * overwriting files in mounted writable volumes * disruption of normal application behavior No unauthenticated exploitation is known. No direct code execution has been demonstrated as part of this issue, though impact may be greater in deployments where the process has broad write permissions. ## Affected versions * **Affected:** 2.1.0 * **Fixed:** 2.1.1 * **Not affected:** earlier releases ## Mitigation Upgrade to **2.1.1**. As a defense-in-depth measure, deployments should continue to ensure the Bugsink process runs with the **minimum required filesystem permissions**.

CVE-2026-40162 Affected Bugsink Versions

1 component(s)
Fixed Versions:
2.1.1
Product / Package Ecosystem Affected Versions Fixed Version
bugsink
pypi/bugsink
PyPI
≥ 2.1.0
< 2.1.1
All 1 versions
2.1.0
2.1.1

References

GitHub Advisory / Wiki ADVISORY
https://github.com/bugsink/bugsink/security/advisories/GHSA-8hw4-fhww-273g
NVD — CVE-2026-40162 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-40162
Bugsink Source Repository REPOSITORY
https://github.com/bugsink/bugsink
Bugsink Release RELEASE
https://github.com/bugsink/bugsink/releases/tag/2.1.1

Frequently Asked Questions

What is CVE-2026-40162?
CVE-2026-40162 is a security vulnerability in Bugsink involving Bugsink affected by authenticated arbitrary file write in artifactbundle/assemble under CWE-20: Improper Input Validation.
Which Bugsink versions are affected?
Affected versions include releases prior to 2.1.1 across affected packages: bugsink.
What version fixes CVE-2026-40162?
Upgrading to 2.1.1 (or the latest patched release for your respective branch) resolves the vulnerability.
Is bugsink affected?
Yes, bugsink is affected in releases prior to 2.1.1. Upgrade your dependency to 2.1.1 or later.
What is the CVSS score of CVE-2026-40162?
CVE-2026-40162 has a CVSS v3.1 base score of 7.1 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:L.
What CWE is associated with CVE-2026-40162?
CVE-2026-40162 is classified under CWE-20: Improper Input Validation (The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.).
How can I check PyPI dependencies for CVE-2026-40162?
Run the dependency tree command: 'pip show bugsink'. 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-8hw4-fhww-273g",
  "modified" : "2026-04-10T19:30:42Z",
  "published" : "2026-04-10T19:30:42Z",
  "aliases" : [ "CVE-2026-40162" ],
  "summary" : "Bugsink affected by authenticated arbitrary file write in artifactbundle/assemble",
  "details" : "# Authenticated arbitrary file write in artifact bundle assembly\n\n## Summary\n\nAn authenticated file write vulnerability was identified in Bugsink **2.1.0** in the artifact bundle assembly flow.\n\nA user with a valid authentication token could cause the application to write attacker-controlled content to a filesystem location writable by the Bugsink process.\n\nThis issue requires authentication and affects only version **2.1.0**.\n\nThe issue is fixed in **2.1.1**.\n\n## Impact\n\nThis vulnerability allows an authenticated user to create or overwrite files **within locations writable by the Bugsink service account**.\n\nThe practical impact depends on the deployment environment and filesystem permissions of the running process.\n\nPossible consequences include:\n\n* modification of application data files\n* corruption of uploaded assets or temporary files\n* overwriting files in mounted writable volumes\n* disruption of normal application behavior\n\nNo unauthenticated exploitation is known.\n\nNo direct code execution has been demonstrated as part of this issue, though impact may be greater in deployments where the process has broad write permissions.\n\n## Affected versions\n\n* **Affected:** 2.1.0\n* **Fixed:** 2.1.1\n* **Not affected:** earlier releases\n\n## Mitigation\n\nUpgrade to **2.1.1**.\n\nAs a defense-in-depth measure, deployments should continue to ensure the Bugsink process runs with the **minimum required filesystem permissions**.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:L"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "bugsink"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "2.1.0"
      }, {
        "fixed" : "2.1.1"
      } ]
    } ],
    "versions" : [ "2.1.0" ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/bugsink/bugsink/security/advisories/GHSA-8hw4-fhww-273g"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-40162"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/bugsink/bugsink"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/bugsink/bugsink/releases/tag/2.1.1"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-20" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-04-10T19:30:42Z",
    "nvd_published_at" : "2026-04-10T18:16:46Z"
  }
}