Vulnerability · Published Sep 15, 2026 · Assigned by CIRCL
CVE-2026-91825MISP: Missing Authorization Check for Event Sharing Group When Distribution Field Is Omitted During Edit
High 7.1
In plain English
A high-severity missing authorization in MISP from MISP. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 33% of all known vulnerabilities).
Official description
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
Affected products (as reported)
Weakness: CWE-862 · Vector: 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
References
- Security patch patch