CVE-2026-43640

Bitwarden Server < 2026.4.1 Authentication Bypass via SCIM API Key

8.6 High

Bitwarden Server prior to v2026.4.1 does not require master-password re-authentication when retrieving or rotating an organization's SCIM API key, allowing an authenticated user with SCIM management privileges to obtain the key using only a valid session.

Attack profile

How easy it is to exploit

Attack vector: Network
Complexity: Low
Privileges needed: Low
User interaction: None

What an attacker can affect

Confidentiality: High
Integrity: High
Availability: None

Exploit likelihood

0.50%Up 0.4 points since May 12, 2026

What each source reports

CVE List Score used 8.6

Bitwarden Server < 2026.4.1 Authentication Bypass via SCIM API Key

Record: CVE-2026-43640
CVSS 4.0: 8.6 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
CVSS 3.1: 8.1 HighCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
Weakness: CWE-303
Updated: 2026-11-02

EUVDEUVD-2026-29171 8.6

Record: EUVD-2026-29171
CVSS 4.0: 8.6 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
Updated: 2026-11-02

GitHub AdvisoriesGHSA-6736-x63f-c628 8.6

Bitwarden Server prior to v2026.4.1 does not require master-password re-authentication when...

Record: GHSA-6736-x63f-c628
CVSS 4.0: 8.6 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CVSS 3.1: 8.1 HighCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
Weakness: CWE-303
Updated: 2026-11-02

NVD 8.6

Record: CVE-2026-43640
CVSS 4.0: 8.6 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CVSS 3.1: 8.1 HighCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
Weakness: CWE-303
Updated: 2026-11-02

OSV 8.6

Bitwarden Server < 2026.4.1 Authentication Bypass via SCIM API Key

Record: CVE-2026-43640
CVSS 4.0: 8.6 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
Weakness: CWE-303
Updated: 2026-11-02

Affected products

History

History
Recorded	Changed	Sources
Nov 2, 2026	first indexed	CVE List, EUVD, GitHub Advisories, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2026-43640 is a high vulnerability (CVSS 8.6) in Bitwarden Server, published May 11, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.50%, the 43rd percentile. No source names a fixed version.