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.
Published: 2026-09-29
Score: 7.7 High
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

No vendor fix or workaround currently provided.

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History

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'}


Subscriptions

Bitwarden Bitwarden
cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-09-29T17:22:11.133Z

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 : Received

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

Modified: 2026-09-29T18:17:06.610

Link: CVE-2026-101878

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-09-29T13:00:06Z

Weaknesses