{"id":"CVE-2026-101878","summary":"Bitwarden Server 2025.6.0 \u003c 2025.6.0 Authentication Bypass via SSO Identifier Truncation","details":"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.","modified":"2026-09-30T03:47:01.547403912Z","published":"2026-09-29T01:58:32.484Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/101xxx/CVE-2026-101878.json","cna_assigner":"VulnCheck","cwe_ids":["CWE-303"]},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/101xxx/CVE-2026-101878.json"},{"type":"ADVISORY","url":"https://github.com/bitwarden/server/releases/tag/v2026.5.0"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-101878"},{"type":"ADVISORY","url":"https://www.vulncheck.com/advisories/bitwarden-server-authentication-bypass-via-sso-identifier-truncation"},{"type":"REPORT","url":"https://github.com/bitwarden/server/pull/7501"},{"type":"FIX","url":"https://github.com/bitwarden/server/commit/27ae3d5455f723975fac03819eaeba8710666bc4"},{"type":"PACKAGE","url":"https://github.com/bitwarden/server"},{"type":"EVIDENCE","url":"https://sanjokkarki.com.np/blog/bitwarden-sso-externalid-truncation"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/bitwarden/server","events":[{"introduced":"1f9849da10f9b9e34887a175e212254884d77798"},{"fixed":"c3cabffccfe35004f5022f91f95cc0fb5e8aa7c4"},{"fixed":"27ae3d5455f723975fac03819eaeba8710666bc4"}],"database_specific":{"extracted_events":[{"introduced":"2025.6.0"},{"fixed":"2026.5.0"}],"source":["DESCRIPTION","REFERENCES"]}}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-101878.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"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"}]}