CVE-2026-91825MISP: Missing Authorization Check for Event Sharing Group When Distribution Field Is Omitted During Edit

Affected versions of MISP fail to authorize a submitted sharing group in a specific event-edit path. The vulnerable logic checked whether the acting user could use a sharing_group_id only when the request explicitly supplied distribution = 4. If the attacker instead omitted distribution but supplied a different sharing_group_id, that authorization branch was skipped. Later, MISP’s field-recovery logic restored the existing event distribution from storage. For events already configured with sharing-group distribution, the unauthorized sharing-group ID could therefore be saved. The fix adds authorization checks in both the controller and Event::_edit() whenever a non-empty sharing_group_id is supplied without distribution. The model now calls SharingGroup::checkIfAuthorised() before persisting the change. Version affected: ≤2.5.45

CVSS

7.1 HIGH (v4.0, CNA)CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:H/VA:N/SC:N/SI:N/SA:N

Weakness (CWE)

CWE-862

Known exploited

Not in CISA's KEV catalog

EPSS (exploitation in the next 30 days)

Not loaded for this CVE

Assigned by

CIRCL

NVD analysis

Deferred

Record last updated

Sep 15, 2026

First seen by InfoSec Signals

Oct 9, 2026

The CVE record on cve.org · NVD's entry

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