CVE-2026-91846 MISP Collection Element Add Missing Authorization on Referenced Object UUID
Attackers can create collection elements referencing private objects via UUIDs, leading to unauthorized disclosure of sensitive data.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-91846?
CVE-2026-91846 is a high-severity missing authorization vulnerability in MISP, published on 15 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Affected versions of MISP allow a collection element to be created from a bare UUID without consistently checking whether the acting user is allowed to access the referenced object.
The commit explains that collection elements themselves only store UUIDs, while the collection view later resolves those UUIDs into their underlying objects. Before this fix, the generic add() path could therefore persist a UUID for an Event or Galaxy Cluster that the caller could not normally read. The patch explicitly notes that this made collections a way to reference another organisation’s private data and had caused disclosure of organisation-only events in the beta collection view.
The fix centralizes authorization in __assertCanUseElements(). Event UUIDs are validated through Event::fetchSimpleEvent() under the current user’s ACL, while Galaxy Cluster UUIDs are checked through GalaxyCluster::fetchGalaxyClusters(). The check is applied both to the CRUD add() path and to addElementToCollection().
Version affected: ≤2.5.45
Which versions are affected by CVE-2026-91846?
How do I fix CVE-2026-91846?
No fix has been published for CVE-2026-91846 yet. Limit exposure of the affected software until one is available.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-91846 being exploited?
There is no known exploitation of CVE-2026-91846 in the wild and no public exploit code.
Sources
Also known as GHSA-wg2v-97w4-3m8g.