CVE-2026-54397
MediumCVSS 6.1Exploitation Probability (EPSS)
Low risk13th percentile — higher than 13% of all known CVEs
Summary
A vulnerability in MISP allows an authenticated user with event edit permissions to manipulate form data and assign an event to a sharing group they are not authorized to use. The issue occurs in the event editing path that does not enforce proper authorization checks.
Risk Assessment
An attacker could exploit this vulnerability to assign an event to an unauthorized sharing group, leading to unauthorized use of restricted groups and disclosure of group names in event listings.
Recommendation
It is recommended to update the system to the latest version, which implements sharing group validation and clears the sharing group ID when the event distribution is not set to sharing group distribution.
Original NVD description (English source)
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.