CVE-2026-43639
Bitwarden Server < 2026.4.0 Missing Authorization via Provider Clients
- State
- Published
- Severity
- 8.9 High
- Published
- May 11, 2026
- Updated
- Jul 14, 2026
- Reserved
- May 1, 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).
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 8.9 High | CVSS:4.0/AV:N/AC:H/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H | VulnCheck |
| 3.1 | 8.0 High | CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H | VulnCheck |
Weaknesses
- CWE-862 Missing Authorization
Affected Products
| Product | Versions |
|---|---|
serverbitwarden |
|
References
- https://sanjokkarki.com.np/blog/bitwarden-provider-takeovertechnical-descriptionexploit
- https://github.com/bitwarden/server/releases/tag/v2026.4.0release-notes
- https://github.com/bitwarden/server/pull/7372issue-tracking
- https://github.com/bitwarden/server/commit/0918bfdda6f5eec391c69bd9074f6aef4eac0b1dpatch
- https://www.vulncheck.com/advisories/bitwarden-server-missing-authorization-via-provider-clientsthird-party-advisory
Every record here comes from the CVE Program’s CVE List. © 1999–2026 The MITRE Corporation. CVE is a registered trademark of The MITRE Corporation. The records are reproduced under the CVE Program terms of use.