CVE intelligence and bounded remediation

CVE-2026-54397 — A vulnerability in MISP’s non-REST event editing path allowed an authenticated user with event edit permissions to manipulate the...

Medium CVSS 6.1

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.

Severity
Medium
CVSS
6.1 (4.0)
Published
2026-06-12
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-863

Affected products

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Matched remediation archetype

Authorization bypass, IDOR, and cross-tenant access

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Map object and action authorization checks across API, UI, batch, import/export, and background-job paths.
  • Identify tenant, ownership, role, and policy boundaries for affected resources and administrative operations.
  • Use synthetic fixtures to compare intended access matrices without accessing another user's real data.

Remediate safely

  • Enforce server-side authorization at each resource access and state transition using the authenticated principal and trusted tenant context.
  • Scope data queries by tenant and ownership; treat client-supplied identifiers, roles, and policy claims as untrusted.
  • Add deny-by-default policy tests for horizontal and vertical access across every affected transport.

Authoritative sources

Complete CVE record and remediation plan

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