CVE-2026-43639

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).

CVSS v3 8.0 HIGH

8.0^/10

CVSS v3 : HIGH

Vector :

Exploitability : 1.3 / Impact : 6.0

Attack Vector NETWORK

Attack Complexity HIGH

Privileges Required HIGH

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope CHANGED

References

Link	Resource
https://github.com/bitwarden/server/commit/0918bfdda6f5eec391c69bd9074f6aef4eac0b1d	Patch
https://github.com/bitwarden/server/pull/7372	Issue Tracking Patch
https://github.com/bitwarden/server/releases/tag/v2026.4.0	Release Notes
https://sanjokkarki.com.np/blog/bitwarden-provider-takeover	Exploit Third Party Advisory
https://www.vulncheck.com/advisories/bitwarden-server-missing-authorization-via-provider-clients	Third Party Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:a:bitwarden:server:*:*:*:*:*:*:*:*

History

26 Oct 2026, 18:10

Type	Values Removed	Values Added
Summary		(es) Bitwarden Server anterior a la v2026.4.0 contiene una vulnerabilidad de autorización faltante que permite a un usuario del servicio de proveedor añadir una organización arbitraria a su proveedor a través de ’POST /providers/{providerId}/clients/existing’, lo que resulta en la toma de control de la organización objetivo; las instalaciones autoalojadas no se ven afectadas ya que este endpoint está restringido a la Nube a través de SelfHosted(NotSelfHostedOnly = true).

Information

Published : 2026-05-11 18:16

Updated : 2026-10-26 18:10

NVD link : CVE-2026-43639

Mitre link : CVE-2026-43639

CVE.ORG link : CVE-2026-43639

JSON object : View

Products Affected

bitwarden

server

CWE

CWE-862

Missing Authorization

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