CVE-2026-101878: Bitwarden Server

High severity, CVSS 7.5. EPSS: 0.3% chance of exploitation in the next 30 days.

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.

Affected products

• Bitwarden Bitwarden Server: from 2025.6.0, before 2026.5.0 (fixed in 2026.5.0)

Published 2026-09-29. Last modified 2026-09-30.