Affected versions of MISP do not consistently enforce the acting user's authorization when instantiating event templates.


For templates using distribution = 4, the template can specify a sharing_group_id. The instantiation path passed that value into event creation without verifying that the user instantiating the template was actually permitted to use the selected sharing group. The commit notes that Event::_add() only performed its own sharing-group authorization in another code path, leaving template instantiation able to write the identifier directly.


The same instantiation path also attached template-specified tags without checking the user's normal tagging permissions. In addition, it hardcoded local => 0, meaning tags marked local_only could be attached globally and consequently propagate through synchronization or export, contrary to their intended restriction.


The fix adds explicit SharingGroup::canUse() authorization for the acting user, applies the same tag-modification checks used by normal event tagging, and ensures local_only tags are attached locally.

Version affected: ≤2.5.45
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Fixes

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Workaround

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History

Thu, 10 Sep 2026 13:30:00 +0000

Type Values Removed Values Added
Description Affected versions of MISP do not consistently enforce the acting user's authorization when instantiating event templates. For templates using distribution = 4, the template can specify a sharing_group_id. The instantiation path passed that value into event creation without verifying that the user instantiating the template was actually permitted to use the selected sharing group. The commit notes that Event::_add() only performed its own sharing-group authorization in another code path, leaving template instantiation able to write the identifier directly. The same instantiation path also attached template-specified tags without checking the user's normal tagging permissions. In addition, it hardcoded local => 0, meaning tags marked local_only could be attached globally and consequently propagate through synchronization or export, contrary to their intended restriction. The fix adds explicit SharingGroup::canUse() authorization for the acting user, applies the same tag-modification checks used by normal event tagging, and ensures local_only tags are attached locally. Version affected: ≤2.5.45
Title MISP Event Template Instantiation Bypasses Sharing Group and Tagging Authorization
Weaknesses CWE-862
References
Metrics cvssV4_0

{'score': 7.1, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N'}


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cve-icon MITRE

Status: PUBLISHED

Assigner: CIRCL

Published:

Updated: 2026-09-10T13:04:03.331Z

Reserved: 2026-09-10T13:04:01.032Z

Link: CVE-2026-88915

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Deferred

Published: 2026-09-10T14:17:19.193

Modified: 2026-09-10T15:13:07.090

Link: CVE-2026-88915

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses