CVE-2026-55836Public exploitNetwork attack vectorHinoki check available

Server-file disclosure via unchecked document import paths

Published Oct 16, 2026 · Updated Oct 16, 2026

Path traversal in Open Zaak document imports allows remote authenticated users to read server files through crafted CSV paths. The _import_document_row function joins the bestandspad field to IMPORT_DOCUMENTEN_BASE_DIR without checking containment, then copies the selected file into downloadable document storage. Exploitation requires an all-authorizations application token and exposes only files readable by the Celery service account.

CVSS severity6.8
Medium
EPSS probability0.39%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Path traversal in Open Zaak document imports allows remote authenticated users to read server files through crafted CSV paths. The _import_document_row function joins the bestandspad field to IMPORT_DOCUMENTEN_BASE_DIR without checking containment, then copies the selected file into downloadable document storage. Exploitation requires an all-authorizations application token and exposes only files readable by the Celery service account.

The record

CVE
CVE-2026-55836
Published
Oct 16, 2026
Updated
Oct 16, 2026
Vendor
OpenZaak
Product
Open Zaak
Classifications
CWE-200, T1005
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 16, 2026CVE publishedPublication date reported by the CVE source.
  2. Oct 16, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=>= 1.13.0, < 1.27.2
  2. Affected versionversion=>= 1.28.0, < 1.28.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

OpenZaak · Open Zaakversion=>= 1.13.0, < 1.27.2; version=>= 1.28.0, < 1.28.2

Published CVSS scores

6.8GitHub CNACVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Activity data is delayed. The latest report is Sep 28, 2026.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-200Exposure of Sensitive Information to an Unauthorized Actor
T1005Data from Local System

Public exploit references

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Technologies

Your stack

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Your stack

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