CVE-2026-43639
Severity CVSS v4.0:
HIGH
Type:
Unavailable / Other
Publication date:
11/05/2026
Last modified:
11/05/2026
Description
Bitwarden Server prior to v2026.4.0 contains a missing authorization vulnerability that allows a provider service user to add an arbitrary organization to their provider via `POST /providers/{providerId}/clients/existing`, resulting in takeover of the target organization; self-hosted installations are unaffected as this endpoint is restricted to Cloud via SelfHosted(NotSelfHostedOnly = true).
Impact
Base Score 4.0
8.90
Severity 4.0
HIGH
Base Score 3.x
8.00
Severity 3.x
HIGH
References to Advisories, Solutions, and Tools
- https://github.com/bitwarden/server/commit/0918bfdda6f5eec391c69bd9074f6aef4eac0b1d
- https://github.com/bitwarden/server/pull/7372
- https://github.com/bitwarden/server/releases/tag/v2026.4.0
- https://sanjokkarki.com.np/blog/bitwarden-provider-takeover
- https://www.vulncheck.com/advisories/bitwarden-server-missing-authorization-via-provider-clients



