CVE-2026-43912 Vaultwarden: Cross-Org Group Binding Enables Unauthorized Read And Write Access Into Another Organization
An attacker with admin rights in one organization can bind foreign memberships to gain unauthorized read and write access to another organization's vault data.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-43912?
CVE-2026-43912 is a high-severity missing authorization vulnerability in dani-garcia vaultwarden, published on 11 May 2026. An attacker needs administrator access to exploit it, with no action from the victim.
Official description
Vaultwarden is a Bitwarden-compatible server written in Rust. Prior to 1.35.5, Vaultwarden does not enforce that a groups_users.users_organizations_uuid entry belongs to the same organization as groups.groups_uuid, or a collections_groups.collections_uuid entry belongs to the same organization as collections_groups.groups_uuid. Multiple organization group-management endpoints accept arbitrary MembershipId and CollectionId values and persist them directly without verifying org consistency. This lets an attacker who is Admin in Organization A, and only a low-privileged member in Organization B bind their Org B membership UUID into an Org A group, then use that foreign group relationship to gain unauthorized access to Org B vault data. With an accessAll=true Org A group, the attacker can make /api/sync and /api/ciphers enumerate Org B ciphers. Once those unauthorized sync results reveal Org B collection IDs, the attacker can also bind those foreign collection IDs to the Org A group and turn the same flaw into write access over Org B items. This vulnerability is fixed in 1.35.5.
Weakness: CWE-285
Which versions are affected by CVE-2026-43912?
It affects 1 product.
Products include Dani-Garcia Vaultwarden.
How do I fix CVE-2026-43912?
No fix has been published for CVE-2026-43912 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-2026-43912 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-43912 exists.
Other vulnerabilities in dani-garcia vaultwarden
- CVE-2024-55225 Vaultwarden vulnerable to user impersonation
- CVE-2024-55224 Vaultwarden HTML injection vulnerability
- CVE-2024-39924 Privilege escalation in n/a
- CVE-2026-27802 Vaultwarden: Privilege Escalation via Bulk Permission Update to Unauthorized Collections by Manager
- CVE-2026-27803 Vaultwarden: Collection Management Operations Allowed Without `manage` Verification for Manager Role
Sources
Also known as GHSA-569v-845w-g82p.