CVE-2026-54397

MISP event editing allows unauthorized assignment to undisclosed sharing groups

Published Jun 12, 2026 CVSS 4.0 · 6.1 Medium EPSS < 1% KEV · Not listed
Description
A vulnerability in MISP’s non-REST event editing path allowed an authenticated user with event edit permissions to manipulate the submitted form data and set an event’s sharing_group_id to a sharing group they were not authorized to use. When distribution was set to sharing group distribution, the non-REST save path accepted the submitted sharing_group_id without performing the same sharing group authorization check enforced by the REST edit path.

An attacker could exploit this by tampering with the event edit request and assigning an event to an undisclosed or unauthorized sharing group. This could result in unauthorized use of restricted sharing groups, disclosure of the sharing group name in event listings, and unintended modification of the event’s distribution metadata.

The issue is fixed by validating that the selected sharing group can be used by the current user when the sharing group is changed, and by clearing sharing_group_id when the event distribution is not set to sharing group distribution.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Metrics ssvc

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

Type Values Removed Values Added
First Time appeared Misp
Misp misp
Vendors & Products Misp
Misp misp
Type Values Removed Values Added
Description A vulnerability in MISP’s non-REST event editing path allowed an authenticated user with event edit permissions to manipulate the submitted form data and set an event’s sharing_group_id to a sharing group they were not authorized to use. When distribution was set to sharing group distribution, the non-REST save path accepted the submitted sharing_group_id without performing the same sharing group authorization check enforced by the REST edit path. An attacker could exploit this by tampering with the event edit request and assigning an event to an undisclosed or unauthorized sharing group. This could result in unauthorized use of restricted sharing groups, disclosure of the sharing group name in event listings, and unintended modification of the event’s distribution metadata. The issue is fixed by validating that the selected sharing group can be used by the current user when the sharing group is changed, and by clearing sharing_group_id when the event distribution is not set to sharing group distribution.
Title MISP event editing allows unauthorized assignment to undisclosed sharing groups
Weaknesses CWE-863
References
Metrics cvssV4_0

{'score': 6.1, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:L/VI:L/VA:N/SC:H/SI:N/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
CIRCL
Published
Updated
Jun 15, 2026, 5:53 PM
Reserved
Jun 12, 2026, 8:55 PM
Status
Deferred
Published
Jun 12, 2026, 9:16 PM
Modified
Jun 17, 2026, 10:58 AM