CVE-2026-43639
HIGHBitwarden Server < 2026.4.0 Missing Authorization via Provider Clients
Title source: cnaDescription
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).
References (5)
Core 5
Core References
Exploit technical-description
exploit
https://sanjokkarki.com.np/blog/bitwarden-provider-takeover
Release Notes release-notes
https://github.com/bitwarden/server/releases/tag/v2026.4.0
Issue Tracking issue-tracking
https://github.com/bitwarden/server/pull/7372
Third Party Advisory third-party-advisory
https://www.vulncheck.com/advisories/bitwarden-server-missing-authorization-via-provider-clients
Scores
CVSS v3
8.0
EPSS
0.0060
EPSS Percentile
43.7%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H
CISA SSVC
Vulnrichment
Exploitation
poc
Automatable
no
Technical Impact
total
Details
CWE
CWE-862
Status
published
Products (1)
bitwarden/server
< 2026.4.0 (2 CPE variants)
Published
May 11, 2026
Tracked Since
May 11, 2026