Affected versions of MISP allow a collection element to be created from a bare UUID without consistently checking whether the acting user is allowed to access the referenced object.


The commit explains that collection elements themselves only store UUIDs, while the collection view later resolves those UUIDs into their underlying objects. Before this fix, the generic add() path could therefore persist a UUID for an Event or Galaxy Cluster that the caller could not normally read. The patch explicitly notes that this made collections a way to reference another organisation’s private data and had caused disclosure of organisation-only events in the beta collection view.


The fix centralizes authorization in __assertCanUseElements(). Event UUIDs are validated through Event::fetchSimpleEvent() under the current user’s ACL, while Galaxy Cluster UUIDs are checked through GalaxyCluster::fetchGalaxyClusters(). The check is applied both to the CRUD add() path and to addElementToCollection().

Version affected: ≤2.5.45
Advisories

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Fixes

Solution

The fix introduces a dedicated __assertCanUseElements() authorization guard that is invoked in the beforeSave callback of the add() CRUD path (covering both form and REST submission) and in addElementToCollection(). For each element UUID, the method resolves the element type (deducing it if the caller omitted the field, preventing bypass by omission) and performs an ACL-aware lookup: for Events it calls fetchSimpleEvent() scoped to the current user, and for GalaxyClusters it calls fetchGalaxyClusters() with the user context. If the object does not exist or the caller lacks access, a NotFoundException is raised and the save is aborted. This ensures that no collection element can reference an object the caller is not authorized to read.


Workaround

No workaround given by the vendor.

History

Tue, 15 Sep 2026 09:45:00 +0000

Type Values Removed Values Added
First Time appeared Misp
Misp misp
Vendors & Products Misp
Misp misp

Tue, 15 Sep 2026 08:45:00 +0000

Type Values Removed Values Added
Description Affected versions of MISP allow a collection element to be created from a bare UUID without consistently checking whether the acting user is allowed to access the referenced object. The commit explains that collection elements themselves only store UUIDs, while the collection view later resolves those UUIDs into their underlying objects. Before this fix, the generic add() path could therefore persist a UUID for an Event or Galaxy Cluster that the caller could not normally read. The patch explicitly notes that this made collections a way to reference another organisation’s private data and had caused disclosure of organisation-only events in the beta collection view. The fix centralizes authorization in __assertCanUseElements(). Event UUIDs are validated through Event::fetchSimpleEvent() under the current user’s ACL, while Galaxy Cluster UUIDs are checked through GalaxyCluster::fetchGalaxyClusters(). The check is applied both to the CRUD add() path and to addElementToCollection(). Version affected: ≤2.5.45
Title MISP Collection Element Add Missing Authorization on Referenced Object UUID
Weaknesses CWE-639
CWE-862
References
Metrics cvssV4_0

{'score': 7.1, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: CIRCL

Published:

Updated: 2026-09-15T13:50:14.847Z

Reserved: 2026-09-15T08:36:20.997Z

Link: CVE-2026-91846

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-09-15T09:16:45.897

Modified: 2026-09-15T14:17:47.767

Link: CVE-2026-91846

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-09-15T09:30:08Z

Weaknesses