CVE-2026-54361: MISP contained multiple mass assignment vulnerabilities in the handling of collections, tag collections, event delegations, and shadow attributes.

MISP contained multiple mass assignment vulnerabilities in the handling of collections, tag collections, event delegations, and shadow attributes.

MISP contained multiple mass assignment vulnerabilities in the handling of collections, tag collections, event delegations, and shadow attributes. Several controller actions accepted user-supplied fields that should have remained server-controlled, including record identifiers and ownership-related fields such as id, org_id, orgc_id, and user_id. An authenticated attacker with access to the affected endpoints could craft requests containing protected fields in order to alter object ownership, redirect an update to another record, overwrite existing event delegation requests, or modify shadow attribute proposals belonging to another organization. This could result in unauthorized modification of MISP objects and, depending on object visibility and sharing configuration, unauthorized access to or transfer of sensitive threat intelligence data. The issue was fixed by explicitly pinning ownership and identity fields to their stored values during edit operations and by removing user-supplied primary keys from create-only save paths. Affected components: * CollectionsController::edit() * EventDelegationsController::delegateEvent() * ShadowAttributesController::edit() * Ta

Description from the National Vulnerability Database, published by 5a6e4751-2f3f-4070-9419-94fb35b644e8

What it means for a small business

If your business uses misp, install the vendor's update. If you're not sure whether you use it, ask whoever manages your computers.

How likely is an attack? The Exploit Prediction Scoring System, run by FIRST (the global association of security response teams), puts the odds of this one being exploited in the next 30 days at 0.26%, higher than 17% of CVEs. That’s low, but low isn’t zero, and the odds jump the day someone publishes an exploit. Scored October 29, 2026, updated daily.

Check your own setup

Website check: reads what your site runs from the outside (WordPress version, plugins it can see, old server software) and matches it against this database.
Server check: what your web server says about itself, and whether that version has known flaws.

Sources

Part of the Huttenlocher Technologies vulnerability database, refreshed twice a day from CISA and the NVD. The title, category and plain-language guidance are ours; check the linked record before acting on a detail. This is general guidance, not a review of your systems.

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