Auth bypass in Open-Zaak
CVE-2026-54657
Open Zaak is an open-source data and services layer for Dutch case-oriented working. From 1.0.0 until 1.27.2, 1.28.2, and 1.29.0, the POST search endpoints /zaken/api/v1/zaken/_zoek and /documenten/api/v1/enkelvoudiginformatieobjecten/_zoek do not filter result querysets according to the authorizations associated with the request token. A caller with a valid zaken.lezen or documenten.lezen token can therefore retrieve case or document metadata outside the token's authorized types or confidentiality levels. Document searches require known UUIDs, and document content remains protected by separate download authorization. This issue is fixed in versions 1.27.2, 1.28.2, and 1.29.0.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
- Open-Zaak — versions >= 1.0.0, < 1.27.2, >= 1.28.0, < 1.28.2
Weakness classification (CWE)
References
- github.com/open-zaak/open-zaak/security/advisories/GHSA-f29q-7rpr-jmjx
- github.com/open-zaak/open-zaak/commit/15456f1a0ef4b0abf1b1c0e3a16c99c15423b9fd
- github.com/open-zaak/open-zaak/commit/4b429d3243d1532f6fe731f932a201cf0ddc4c18
- github.com/open-zaak/open-zaak/commit/d3869af98c60570782f867bab3e1d14fd8d8330f
- github.com/open-zaak/open-zaak/releases/tag/1.27.2
- github.com/open-zaak/open-zaak/releases/tag/1.28.2
- github.com/open-zaak/open-zaak/releases/tag/1.29.0
Frequently asked questions
- What is CVE-2026-54657?
- CVE-2026-54657 is a medium-severity vulnerability in Open-Zaak, classified under Improper Authorization. CVSS score: 6.5/10. Published 2026-10-16.
- How severe is CVE-2026-54657?
- Medium severity. CVSS v3 base score is 6.5 out of 10.