Bitwarden Server 2025.6.0 before 2026.5.0 declares the @ExternalId parameter of the User_ReadBySsoUserOrganizationIdExternalId stored procedure as NVARCHAR(50) while the column it queries stores NVARCHAR(300), silently truncating the SSO login identifier on SQL Server deployments and allowing a user whose identity-provider identifier begins with another organization member's full 50-character identifier to authenticate as that member and obtain a victim-scoped access token.
History

Thu, 01 Oct 2026 19:45:00 +0000

Type Values Removed Values Added
First Time appeared Bitwarden server
CPEs cpe:2.3:a:bitwarden:server:*:*:*:*:*:*:*:*
Vendors & Products Bitwarden server

Tue, 29 Sep 2026 18:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'total'}, 'version': '2.0.3'}


Tue, 29 Sep 2026 13:15:00 +0000

Type Values Removed Values Added
First Time appeared Bitwarden
Bitwarden bitwarden
Vendors & Products Bitwarden
Bitwarden bitwarden

Tue, 29 Sep 2026 02:15:00 +0000

Type Values Removed Values Added
Description Bitwarden Server 2025.6.0 before 2026.5.0 declares the @ExternalId parameter of the User_ReadBySsoUserOrganizationIdExternalId stored procedure as NVARCHAR(50) while the column it queries stores NVARCHAR(300), silently truncating the SSO login identifier on SQL Server deployments and allowing a user whose identity-provider identifier begins with another organization member's full 50-character identifier to authenticate as that member and obtain a victim-scoped access token.
Title Bitwarden Server 2025.6.0 < 2025.6.0 Authentication Bypass via SSO Identifier Truncation
Weaknesses CWE-303
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H'}

cvssV4_0

{'score': 7.7, 'vector': 'CVSS:4.0/AV:N/AC:H/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N'}


cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published: 2026-09-29T01:58:32.484Z

Updated: 2026-10-01T19:19:18.222Z

Reserved: 2026-09-28T15:44:45.389Z

Link: CVE-2026-101878

cve-icon Vulnrichment

Updated: 2026-09-29T17:21:57.658Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-09-29T02:16:54.990

Modified: 2026-09-30T17:23:08.953

Link: CVE-2026-101878

cve-icon Redhat

No data.