---
id: "CVE-2026-55836"
kind: "vulnerability"
aliases: ["CVE-2026-55836"]
title: "Open Zaak: CSV import path lets authorized client read server files"
severity: "medium"
cvss: 6.8
epss: null
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["celery", "document-import", "open-zaak", "package", "self-hosted"]
not_affected_if: ["fixed-version", "narrow-token-scopes", "no-csv-document-import"]
published_at: "2026-10-16T16:18:43+00:00"
first_seen_at: "2026-10-23T21:57:13+00:00"
updated_at: "2026-10-25T03:45:11+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-55836", "first_seen_at": "2026-10-23T21:57:13+00:00"}]
---

# Open Zaak: CSV import path lets authorized client read server files

Open Zaak's document import task does not confine the bestandspad path in uploaded CSV rows to the configured import directory. A client with an all-authorizations application token can point it at any file the Celery worker can read, and the worker copies that file into document storage where it can be downloaded.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Check the installed Open Zaak version and compare it to the fixed releases listed in the fix field.
- Look for IMPORT_DOCUMENTEN_BASE_DIR in the deployment settings to confirm whether document CSV imports are configured.
- Review which application tokens hold all authorizations.

## Fix

- Upgrade Open Zaak to `1.27.2`, `1.28.2`, or `1.29.0`, matching your release line.
- Rotate application tokens that hold all authorizations if they may have been misused.

## Timeline

- 2026-10-23T21:57:13+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-55836

## From the sources

Open Zaak is an open-source data and services layer for Dutch case-oriented working. From 1.13.0 until 1.27.2, 1.28.2, and 1.29.0, _import_document_row in src/openzaak/components/documenten/tasks.py uses the attacker-controlled bestandspad CSV field without ensuring that the resolved path remains under IMPORT_DOCUMENTEN_BASE_DIR. A client with an all-authorizations application token can supply an absolute or parent-traversal path to a file readable by the Celery service account. The worker copies that file into document storage, allowing its contents to be retrieved through the normal document download API and exposing server secrets or other private files. This issue is fixed in versions 1.27.2, 1.28.2, and 1.29.0.

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