CVE-2026-93854 Missing authorization in Blazar
Authenticated users can modify or delete other users' leases due to a parameter mismatch in authorization checks, bypassing ownership restrictions.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-93854?
CVE-2026-93854 is a high-severity missing authorization vulnerability in OpenStack Blazar, published on 18 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
In OpenStack Blazar before 17.0.1, the V2 lease API does not enforce object-level authorization on its update and delete operations (PUT /v2/leases/{lease_id} and DELETE /v2/leases/{lease_id}). The policy authorize() wrapper attempts to load the target lease to build the authorization target from its owner, but it looks up the lease under the keyword "lease_id" whereas the controller methods name the parameter "id" (and the wsme_pecan.wsexpose wrapper delivers it positionally). The lookup returns None, and thus authorization falls back to the requesting user's own project_id/user_id instead of the target lease owner. Any authenticated user who knows a lease ID can therefore modify or delete leases belonging to other users and projects, bypassing the intended ownership check.
Weakness: CWE-1025
Which versions are affected by CVE-2026-93854?
How do I fix CVE-2026-93854?
Upgrade to a fixed version.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-93854 being exploited?
There is no known exploitation of CVE-2026-93854 in the wild and no public exploit code.
Sources
Also known as DEBIAN-CVE-2026-93854, GHSA-4rvg-j972-3xw2, UBUNTU-CVE-2026-93854.