{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "extracted_events": [
              {
                "introduced": "2025.6.0"
              },
              {
                "fixed": "2026.5.0"
              }
            ],
            "source": [
              "DESCRIPTION",
              "REFERENCES"
            ]
          },
          "events": [
            {
              "introduced": "1f9849da10f9b9e34887a175e212254884d77798"
            },
            {
              "fixed": "c3cabffccfe35004f5022f91f95cc0fb5e8aa7c4"
            },
            {
              "fixed": "27ae3d5455f723975fac03819eaeba8710666bc4"
            }
          ],
          "repo": "https://github.com/bitwarden/server",
          "type": "GIT"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "VulnCheck",
    "cwe_ids": [
      "CWE-303"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/101xxx/CVE-2026-101878.json"
  },
  "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.",
  "id": "CVE-2026-101878",
  "modified": "2026-09-30T03:30:59.792229249Z",
  "published": "2026-09-29T01:58:32.484Z",
  "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"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "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",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Bitwarden Server 2025.6.0 \u003c 2025.6.0 Authentication Bypass via SSO Identifier Truncation"
}