CVE-2026-91825

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

Scoring

Severity
HIGH
CVSS base score
7.1
CVSS 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
EPSS probability
0.24%
CWE
CWE-862
Published
2026-09-15
Last modified
2026-09-15

Affected products

Weakness type

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