Bitwarden Server before 2026.5.0 contains a privilege escalation vulnerability that allows authenticated Custom users with ManageUsers permission to remove Admin accounts from an organization by exploiting a missing role hierarchy check in the bulk user-remove endpoint. Attackers can supply Admin organization-user IDs in a bulk DELETE request to bypass the guard enforced on the single-user removal path, effectively removing one or more Admin accounts from an organization.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Attack Requirements
None
No additional conditions
Privileges Required
Low
Basic privileges needed
User Interaction
None
No user interaction needed
Impact Assessment
Confidentiality
None
No data leak
Integrity
High
Complete data modification
Availability
Low
Partial disruption
CVSS Vector v4.0
Weakness Type (CWE)
Vulnerable Products 1
| Configuration | From (including) | Up to (excluding) |
|---|---|---|
|
Bitwarden Server
cpe:2.3:a:bitwarden:server:*:*:*:*:*:*:*:*
|
— |
2026.5.0
|
References 5
https://github.com/bitwarden/server/commit/901bb67157c0f80d369c40b76742fdf7623d…
disclosure@vulncheck.com
https://github.com/bitwarden/server/pull/7526
disclosure@vulncheck.com
https://github.com/bitwarden/server/releases/tag/v2026.5.0
disclosure@vulncheck.com
https://sanjokkarki.com.np/blog/bitwarden-bulk-remove-admin
disclosure@vulncheck.com
https://www.vulncheck.com/advisories/bitwarden-server-privilege-escalation-via-…
disclosure@vulncheck.com