CVE-2026-43639
criticalBitwarden Server prior to v2026.4.0 contains a missing authorization vulnerability that allows a provider service user to add an arbitrary organization to thei…
Vendor / product: Bitwarden — server
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
9.1
9.1 (CVSS v3.1)
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H Severity source: NVD CVSS v3.1 (nvd@nist.gov)
Timeline (UTC)
Published: 2026-05-11 18:16
Modified: 2026-10-26 18:10
NVD status: Analyzed
Last synced 2 days ago
Verified against the source API 2026-10-27 07:07 UTC
Exploitation
Not listed in CISA KEV (as of last catalog sync)
Absence from KEV does not mean a CVE is not exploited. Exploitation status: unknown (no authoritative evidence in our sources).
Affected products
bitwarden / server <2026.4.0
Weakness classification (CWE)
Source: NVD / CISA. “NVD-CWE-Other” and “NVD-CWE-noinfo” mean NVD could not assign a specific weakness.
Mitigation & advisories
Patch / mitigation: https://github.com/bitwarden/server/commit/0918bfdda6f5eec391c69bd9074f6aef4eac0b1d
Patch / mitigation: https://github.com/bitwarden/server/pull/7372
References
- https://github.com/bitwarden/server/commit/0918bfdda6f5eec391c69bd9074f6aef4eac0b1d disclosure@vulncheck.com
- https://github.com/bitwarden/server/pull/7372 disclosure@vulncheck.com
- https://github.com/bitwarden/server/releases/tag/v2026.4.0 disclosure@vulncheck.com
- https://sanjokkarki.com.np/blog/bitwarden-provider-takeover disclosure@vulncheck.com
- https://www.vulncheck.com/advisories/bitwarden-server-missing-authorization-via-provider-c... disclosure@vulncheck.com
Data sources
NVD CVE API 2.0 — fetched 2026-10-27 07:07 UTC · record ↗