CVE-2026-104912

MISP Correlation Authorization Bypass Exposes Restricted Event and Attribute Data

Published Oct 2, 2026 CVSS 4.0 · 7.1 High EPSS < 1% KEV · Not listed
Description
MISP contains an authorization flaw in its correlation handling during attribute searches. When a user performs an attribute search that triggers correlation lookups, the system authorized access to correlated attributes and events based on a stale distribution snapshot stored on the correlation row rather than the live event access control list.

Because the correlation row's distribution columns are a point-in-time copy that lacks a published flag, the authorization check becomes incorrect when an event is subsequently restricted (for example, its sharing group is changed or it is unpublished). As a result, an authenticated user could retrieve attributes and event details belonging to events they no longer have permission to view.

Preconditions:

- An authenticated user with at least read access to some events in the instance.

- The existence of correlations between events, at least one of which has been restricted after the correlation was created.

Impact:

- Confidentiality: exposure of attribute values and event metadata that the user is not authorized to access.

Affected versions: MISP prior to v2.5.48.

Remediation

Vendor Solution

The fix ensures that correlation-based lookups are authorized against the live event and attribute access control lists rather than the stale distribution snapshot on the correlation row. A new filtering step validates related event IDs against the current event ACL before returning them, and attribute queries for non-admin users now include the live ACL conditions. Additionally, Event and Object fields are stripped from returned attribute results to prevent incidental metadata leakage.

Tracking

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Advisories

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History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description MISP contains an authorization flaw in its correlation handling during attribute searches. When a user performs an attribute search that triggers correlation lookups, the system authorized access to correlated attributes and events based on a stale distribution snapshot stored on the correlation row rather than the live event access control list. Because the correlation row's distribution columns are a point-in-time copy that lacks a published flag, the authorization check becomes incorrect when an event is subsequently restricted (for example, its sharing group is changed or it is unpublished). As a result, an authenticated user could retrieve attributes and event details belonging to events they no longer have permission to view. Preconditions: - An authenticated user with at least read access to some events in the instance. - The existence of correlations between events, at least one of which has been restricted after the correlation was created. Impact: - Confidentiality: exposure of attribute values and event metadata that the user is not authorized to access. Affected versions: MISP prior to v2.5.48.
Title MISP Correlation Authorization Bypass Exposes Restricted Event and Attribute Data
First Time appeared Misp
Misp misp
Weaknesses CWE-284
CWE-862
CPEs cpe:2.3:a:misp:misp:*:*:*:*:*:*:*:*
Vendors & Products Misp
Misp misp
References
Metrics cvssV4_0

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

Weaknesses

Sources

Status
PUBLISHED
Assigner
CIRCL
Published
Updated
Oct 3, 2026, 3:52 PM
Reserved
Oct 2, 2026, 4:04 PM
Status
Deferred
Published
Oct 2, 2026, 4:16 PM
Modified
Oct 3, 2026, 4:16 PM