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Advisories

Bitwarden Server 2025.6.0 < 2025.6.0 Authentication Bypass via SSO Identifier Truncation

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severity
high
date
Affecting

  • bitwarden server >= 2025.6.0, < 2026.5.0

CWE
  • CWE-303 Incorrect Implementation of Authentication Algorithm
CVSS
7.7
CVSS V4 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
Credit
Sanjok Karki
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.

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