Vulnerability · Published Oct 16, 2026 · Assigned by GitHub_M
CVE-2026-55836Open Zaak: Path traversal / arbitrary server-file read via Documenten API document import (bestandspad)
Medium 6.8
In plain English
A medium-severity information exposure in open-zaak from open-zaak. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 33% of all known vulnerabilities).
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.
Affected products (as reported)
Weakness: CWE-200 · Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:N/A:N
References
- https://github.com/open-zaak/open-zaak/security/advisories/GHSA-x5cj-23hr-5r54 x_refsource_CONFIRM
- https://github.com/open-zaak/open-zaak/commit/4b23957b55ab792bc2ba1fbc5ce6918881b62ab8 x_refsource_MISC
- https://github.com/open-zaak/open-zaak/commit/69c78ce2a0edb45bec8809bc2205585c5f8a4054 x_refsource_MISC
- https://github.com/open-zaak/open-zaak/commit/8acd5e59e0132aa19284bf22f7b3defca279e2ce x_refsource_MISC
- https://github.com/open-zaak/open-zaak/releases/tag/1.27.2 x_refsource_MISC
- https://github.com/open-zaak/open-zaak/releases/tag/1.28.2 x_refsource_MISC
- https://github.com/open-zaak/open-zaak/releases/tag/1.29.0 x_refsource_MISC