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).
Fix
Patch, vendor advisory and mitigation references on NVD 2
- https://github.com/bitwarden/server/commit/0918bfdda6f5eec391c69bd9074f6aef4eac0b1d Patch
- https://github.com/bitwarden/server/pull/7372 Issue Tracking, Patch
Every line above is quoted from NVD, CISA, Microsoft, the vendor's own advisory or DISA; nothing is generated.
Change history 1
- First seenCVSS 8.9 · bitwardenNVD modified 2026-10-26 18:10
Affected (CPE criteria) 1
cpe:2.3:a:bitwarden:server:*:*:*:*:*:*:*:*
References 5
- 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