CVE-2026-86342
Received Received - Intake

Improper Authorization in MISP Feed Preview

Publication date: 2026-09-07

Last updated on: 2026-09-07

Assigner: CIRCL

Description
Affected versions of MISP contain improper authorization checks in the freetext feed preview functionality. The preview performed correlation lookups against attributes from events without applying the requesting user's ACL, allowing restricted event correlations and associated event information to be exposed to users who could not otherwise access those events. The vulnerable queries were scoped only by attribute values and deletion status rather than MISP's event, organization, sharing-group, attribute, and object-level access controls. The same preview functionality also returned cross-feed correlation information without properly restricting the feed list to feeds visible to the caller. This exposed metadata for feeds that were not marked lookup_visible; one affected response additionally included the configured feed URL even though that value was not required by the feature. The fixes apply the caller's ACL to attribute correlation searches, remove feed URLs from correlation results, restrict cross-feed results according to feed visibility, and correct host-organization ID comparison so the authorization rules are applied consistently. Version affected: ≤2.5.45

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Meta Information

Published
2026-09-07
Last Modified
2026-09-07
Generated
2026-09-07
AI Q&A
2026-09-07
EPSS Evaluated
N/A
NVD
CVE-2026-86342
EUVD
EUVD-2026-72319

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
misp misp to 2.5.45 (inc)

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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

This vulnerability in MISP versions 2.5.45 and earlier involves improper authorization checks in the freetext feed preview feature. The system performed attribute correlation lookups without applying the user's access control list (ACL), exposing restricted event data to unauthorized users. It also disclosed metadata for non-visible feeds and included feed URLs in correlation results despite not being required.

Detection Guidance

To detect this vulnerability, check if your MISP instance is running a version ≤2.5.45. Use commands like 'misp --version' or check the web interface's footer for version info. Review logs for unauthorized access attempts to restricted event correlations or feed metadata.

Impact Analysis

Unauthorized users could view event correlations and information they shouldn't access, including restricted feeds and their URLs. This could lead to data leaks of sensitive information shared within the MISP platform.

Compliance Impact

This vulnerability could violate compliance requirements by exposing sensitive data to unauthorized users, potentially breaching confidentiality obligations under GDPR, HIPAA, or other regulations that mandate strict access controls for shared threat intelligence data.

Mitigation Strategies

Immediately upgrade MISP to a version beyond 2.5.45. If upgrading is not possible, apply the security patches from the referenced GitHub commits (dedb4b297, 1fb622046, dc1a0f7c2, 4b6916086). Disable the freetext feed preview feature if not required.

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