# CVE-2026-55836: Open Zaak: Path traversal / arbitrary server-file read via Documenten API document import (bestandspad)

> An attacker with an application token can use path traversal in the document import API to read arbitrary server files via the Celery worker.

- **Severity:** Medium 6.8 (`CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 16 Oct 2026
- **Updated:** 16 Oct 2026
- **Also known as:** GHSA-x5cj-23hr-5r54

## What is CVE-2026-55836?

CVE-2026-55836 is a medium-severity path traversal vulnerability in open-zaak, published on 16 Oct 2026. An attacker needs administrator access to exploit it, with no action from the victim.

### Official description

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.

Weakness: CWE-200 (Exposure of Sensitive Information to an Unauthorized Actor)

## Which versions are affected by CVE-2026-55836?


## How do I fix CVE-2026-55836?

No fix has been published for CVE-2026-55836 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-55836 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-55836 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-55836 and fix it if it is affected.

What it is: CVE-2026-55836 is a medium-severity path traversal vulnerability in open-zaak, published on 16 Oct 2026. An attacker needs administrator access to exploit it, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-55836 exists.

Affected product: open-zaak. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-55836/ (Markdown: https://insights.sbomify.com/CVE-2026-55836/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-55836
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-55836
- OSV: https://osv.dev/vulnerability/CVE-2026-55836

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-55836/
Summaries are generated and may contain mistakes; the official description above is the record.