PT-2026-39716 · Bitwarden · Server

Sanjok Karki · Published 2026-05-11 · Updated 2026-05-11 · CVE-2026-43639

NVD

CVSS v3.1

8.0

High

Base vector

AV:N/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H

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).

Exploit

Fix

Missing Authorization

Weakness Enumeration

CWE-862

Related Identifiers

CVE-2026-43639

Affected Products

Server

References · 6

• 🔥 https://sanjokkarki.com.np/blog/bitwarden-provider-takeover · Exploit
• https://nvd.nist.gov/vuln/detail/CVE-2026-43639 · Security Note
• https://github.com/bitwarden/server/commit/0918bfdda6f5eec391c69bd9074f6aef4eac0b1d · Patch
• https://github.com/bitwarden/server/pull/7372 · Note
• https://github.com/bitwarden/server/releases/tag/v2026.4.0 · Note
• https://vulncheck.com/advisories/bitwarden-server-missing-authorization-via-provider-clients · Note