CVE-2026-88915

MISP Event Template Instantiation Bypasses Sharing Group and Tagging Authorization

HIGH
7.1
CVSS Score
Published: September 10, 2026 at 01:04 PM UTC
Updated: September 10, 2026 at 06:18 PM UTC
1 product affected across 1 vendorMISP

Using MISP by MISP?

Get instant alerts when new vulnerabilities affect MISP - before attackers find them.

Real-time alertsTrack your software stackFree plan available
Severity
HIGH7.1
Exploit prediction
EPSS 0.4%
SSVC
No known exploit

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

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v ≤ 2.5.45

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (1)

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.1HIGHCIRCL
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-862

Get alerted

Stop reading CVE feeds looking for your own stack

Track the products you run and VulnTracker tells you when a new CVE affects them — with what is known about fixing it, and nothing about the rest.

Free plan, no card