Bugsink affected by authenticated arbitrary file write in artifactbundle/assemble

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

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

EPSS

• CVE-2026-40162: 0.30% estimated exploitation activity in the next 30 days; percentile 22.65 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

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…

Published by the source

10 Apr 2026, 19:30 UTC

Last modified by the source

13 Jul 2026, 16:42 UTC

Source last checked

26 Oct 2026, 13:40 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-8hw4-fhww-273g

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-8hw4-fhww-273g

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# Patch Next advisory brief: CVE-2026-40162

Advisory: Bugsink affected by authenticated arbitrary file write in artifactbundle/assemble
IDs: CVE-2026-40162, GHSA-8hw4-fhww-273g
Record: https://patchnext.com/advisories/cve-2026-40162 (revision 2, source checked 26 Oct 2026, 13:40 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.1)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: bugsink 2.1.1. A vendor fix does not mean a deployment is fixed.

## Affected components
- PyPI bugsink: affected >= 2.1.0, <= 2.1.0; fixed in 2.1.1

## Suggested inspection (read-only)
- `python -m pip show bugsink`: prints the installed version. Run with the environment that serves production active.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on bugsink.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-8hw4-fhww-273g (OSV record GHSA-8hw4-fhww-273g lists affected ranges: PyPI bugsink >=2.1.0 <2.1.1 (fixed))
- Verified: https://github.com/advisories/GHSA-8hw4-fhww-273g (GitHub-reviewed advisory GHSA-8hw4-fhww-273g lists affected ranges: PyPI bugsink >=2.1.0 <=2.1.0)

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