CVE-2026-85226
Received Received - Intake

Authorization Bypass in MISP OnDemand Correlation Engine

Publication date: 2026-09-03

Last updated on: 2026-09-03

Assigner: CIRCL

Description
MISP contains an authorization flaw in the OnDemand correlation engine where correlations were calculated solely from matching attribute values without applying the distribution, sharing group, organization, or other access-control restrictions associated with the correlated attributes and events. As a result, an authenticated user could receive correlation results referring to attributes or events that the user was not authorized to access. The vulnerable correlation collection path did not take the requesting user into account. The patch changes the correlation collector to accept the current user and filters the resulting attribute identifiers through MISP's existing fetchAttributesSimple() authorization logic, which evaluates event-, attribute-, object-, distribution-, and sharing-group-level restrictions against the live data. The issue also affected paths relying on previously stored correlation data. Because the OnDemand engine does not maintain the stored correlation table, its denormalized access-control information could be stale. The patch therefore validates correlated attribute identifiers against the current ACLs before returning them and additionally applies normal event visibility conditions when retrieving related events. An authenticated low-privileged user could exploit this issue by querying or creating attributes that correlate with restricted MISP content, potentially learning information about otherwise inaccessible events or attributes.

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Meta Information

Published
2026-09-03
Last Modified
2026-09-03
Generated
2026-09-03
AI Q&A
2026-09-03
EPSS Evaluated
N/A
NVD
CVE-2026-85226
EUVD
EUVD-2026-70499

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
misp misp *

Helpful Resources

Exploitability

CWE
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KEV
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CWE ID Description
CWE-862 The product does not perform an authorization check when an actor attempts to access a resource or perform an action.

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Executive Summary

MISP has an authorization flaw in its OnDemand correlation engine where correlations were calculated without considering access-control restrictions like distribution, sharing groups, or organization permissions. This allowed authenticated users to see correlation results for attributes or events they were not authorized to access.

Detection Guidance

To detect this vulnerability, monitor MISP logs for unauthorized correlation queries or access attempts to restricted attributes or events. Check for discrepancies between user permissions and accessed data. No specific commands are provided in the context.

Impact Analysis

An authenticated low-privileged user could exploit this by querying or creating attributes that correlate with restricted MISP content, potentially learning information about otherwise inaccessible events or attributes.

Mitigation Strategies

Apply the patch that modifies the correlation collector to enforce user-specific access controls. Validate correlated attribute identifiers against current ACLs before returning results. Ensure event visibility conditions are applied when retrieving related events.

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