CVE-2026-43639
Published:May 11, 2026
Updated:May 16, 2026
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).
Affected Packages
https://github.com/bitwarden/server.git (GITHUB):
Affected version(s) >=v1.0.0 <v2026.4.0Fix Suggestion:
Update to version v2026.4.0Related Resources (5)
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Contact UsCVSS v4
Base Score:
8.9
Attack Vector
NETWORK
Attack Complexity
HIGH
Attack Requirements
NONE
Privileges Required
HIGH
User Interaction
NONE
Vulnerable System Confidentiality
HIGH
Vulnerable System Integrity
HIGH
Vulnerable System Availability
HIGH
Subsequent System Confidentiality
HIGH
Subsequent System Integrity
HIGH
Subsequent System Availability
HIGH
CVSS v3
Base Score:
8
Attack Vector
NETWORK
Attack Complexity
HIGH
Privileges Required
HIGH
User Interaction
NONE
Scope
CHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Weakness Type (CWE)
Missing Authorization
EPSS
Base Score:
0.05