{"id":"CVE-2026-101878","aliases":["EUVD-2026-88605","GHSA-2fcc-4gv4-mvr7"],"status":"published","title":"Bitwarden Server 2025.6.0 \u003c 2025.6.0 Authentication Bypass via SSO Identifier Truncation","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.","severity":{"version":"4.0","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","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.00258,"percentile":0.17628,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-303"],"published":"2026-09-29T01:58:32Z","modified":"2026-11-09T02:46:51Z","products":[{"vendor":"bitwarden","product":"bitwarden server"}],"references":[{"url":"https://sanjokkarki.com.np/blog/bitwarden-sso-externalid-truncation","tags":["technical-description","exploit","evidence"]},{"url":"https://github.com/bitwarden/server/releases/tag/v2026.5.0","tags":["release-notes","advisory"]},{"url":"https://github.com/bitwarden/server/pull/7501","tags":["issue-tracking","patch","fix"]},{"url":"https://github.com/bitwarden/server/commit/27ae3d5455f723975fac03819eaeba8710666bc4","tags":["patch","fix"]},{"url":"https://www.vulncheck.com/advisories/bitwarden-server-authentication-bypass-via-sso-identifier-truncation","tags":["third-party-advisory","advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-101878","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-2fcc-4gv4-mvr7"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/101xxx/CVE-2026-101878.json","tags":["advisory"]},{"url":"https://github.com/bitwarden/server","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2026-101878","title":"Bitwarden Server 2025.6.0 \u003c 2025.6.0 Authentication Bypass via SSO Identifier Truncation","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.","status":"published","published":"2026-09-29T01:58:32.484Z","modified":"2026-11-08T14:00:42.524Z","cvss":[{"version":"4.0","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","level":"high","assessor":"cna"},{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high","assessor":"cna"}],"cwes":["CWE-303"],"updated_at":"2026-11-08T14:43:22.764053Z"}],"euvd":[{"id":"EUVD-2026-88605","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.","status":"published","published":"2026-09-29T01:58:32Z","modified":"2026-11-08T14:00:42Z","cvss":[{"version":"4.0","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","level":"high"}],"updated_at":"2026-11-08T15:13:09.785497Z"}],"ghsa":[{"id":"GHSA-2fcc-4gv4-mvr7","title":"Bitwarden Server 2025.6.0 before 2026.5.0 declares the @ExternalId parameter of the...","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.","status":"published","published":"2026-09-29T03:30:41Z","modified":"2026-09-29T03:30:47Z","cvss":[{"version":"4.0","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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"high"},{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high"}],"cwes":["CWE-303"],"updated_at":"2026-11-02T15:12:32.639211Z"}],"nvd":[{"id":"CVE-2026-101878","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.","status":"published","published":"2026-09-29T02:16:54.99Z","modified":"2026-09-30T17:23:08.953Z","cvss":[{"version":"4.0","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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"high","assessor":"secondary"},{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high","assessor":"secondary"}],"cwes":["CWE-303"],"updated_at":"2026-11-02T14:12:52.413234Z"}],"osv":[{"id":"CVE-2026-101878","title":"Bitwarden Server 2025.6.0 \u003c 2025.6.0 Authentication Bypass via SSO Identifier Truncation","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.","status":"published","published":"2026-09-29T01:58:32.484Z","modified":"2026-11-11T02:49:13.057664273Z","cvss":[{"version":"4.0","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","level":"high"}],"cwes":["CWE-303"],"updated_at":"2026-11-09T03:16:24.800471Z"}]}}