In MISP, the CollectionsController add() method enforced the sharing-group usability authorization check and element capture only when the HTTP request method was POST. However, the underlying CRUDComponent::add() method persists data on both POST and PUT requests. As a result, an authenticated user could issue a PUT request to the collections/add endpoint, bypassing the sharing-group authorization check entirely. This allowed the creation of a collection with distribution=4 (shared with a specific sharing group) targeting a sharing group that the user was not authorized to use. The bypassed check would normally verify that the current user has access to the specified sharing group before allowing the collection to be associated with it. The security impact is that an authenticated user can place collection data into a sharing group context they do not have legitimate access to, potentially exposing that data to all members of the unauthorized sharing group and violating the intended access-control boundaries of the MISP instance. The vulnerability requires an authenticated session and knowledge of a valid sharing group identifier; no user interaction or special tooling is needed beyond sending a PUT request instead of a POST request to the same endpoint.
History

Wed, 23 Sep 2026 15:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Tue, 22 Sep 2026 16:00:00 +0000

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

Tue, 22 Sep 2026 13:30:00 +0000

Type Values Removed Values Added
Description In MISP, the CollectionsController add() method enforced the sharing-group usability authorization check and element capture only when the HTTP request method was POST. However, the underlying CRUDComponent::add() method persists data on both POST and PUT requests. As a result, an authenticated user could issue a PUT request to the collections/add endpoint, bypassing the sharing-group authorization check entirely. This allowed the creation of a collection with distribution=4 (shared with a specific sharing group) targeting a sharing group that the user was not authorized to use. The bypassed check would normally verify that the current user has access to the specified sharing group before allowing the collection to be associated with it. The security impact is that an authenticated user can place collection data into a sharing group context they do not have legitimate access to, potentially exposing that data to all members of the unauthorized sharing group and violating the intended access-control boundaries of the MISP instance. The vulnerability requires an authenticated session and knowledge of a valid sharing group identifier; no user interaction or special tooling is needed beyond sending a PUT request instead of a POST request to the same endpoint.
Title MISP Collections: Missing Authorization Check for Sharing Group on PUT Request in collections/add
Weaknesses CWE-285
CWE-862
References
Metrics cvssV4_0

{'score': 5.3, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:L/SA:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: CIRCL

Published: 2026-09-22T13:20:25.683Z

Updated: 2026-09-22T15:32:21.567Z

Reserved: 2026-09-22T13:20:20.466Z

Link: CVE-2026-95671

cve-icon Vulnrichment

Updated: 2026-09-22T15:32:18.751Z

cve-icon NVD

Status : Deferred

Published: 2026-09-22T14:17:21.747

Modified: 2026-09-22T16:18:22.057

Link: CVE-2026-95671

cve-icon Redhat

No data.