CVE-2026-101878 (GCVE-0-2026-101878)

Vulnerability from cvelistv5 – Published: 2026-09-29 01:58 – Updated: 2026-11-08 14:00 X_Open Source
VLAI
Title
Bitwarden Server 2025.6.0 < 2025.6.0 Authentication Bypass via SSO Identifier Truncation
Summary
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
7.7 (High)
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
7.5 (High)
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
SSVC
Exploitation: poc Automatable: no Technical Impact: total
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-09-29 17:21 UTC
CWE
  • CWE-303 - Incorrect Implementation of Authentication Algorithm
Assigner
VulnCheck CNA under the mitre root
CNA scorecard B 84/100 over 8103 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
bitwarden bitwarden server Affected: 2025.6.0 , < 2026.5.0 (custom)
    cpe:2.3:a:bitwarden:server:*:*:*:*:*:*:*:*
Create a notification for this product.
Date Public
2026-04-29 00:00
Credits
Sanjok Karki
Show details on NVD website
To clipboard 

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}



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How durations are calculated

Following the VTEM framework (Black Hat USA 2015), time to patch starts when the vendor or a coordinator was informed, total time to patch at discovery, and disclosure to patch at public disclosure; vendor response time runs from the report to its acknowledgement. Time to exploit and time unpatched start at the earliest discovery or report, falling back to public disclosure. Unpatched time ends at the first recorded patch, or the calculation time when no patch is recorded. Exploitation to patch shows the interval between those two events; a published proof of concept is a public exploit, not exploitation.

Each result shows its source dates. A negative interval means the end event came first; when date-only inputs leave the order open, the result says so. Date-only inputs are approximate. The earliest evidence wins: KEV report dates and sightings are labelled as such. Records describing another vulnerability are listed but never calculated from, and a PoC alone does not establish exploitation. Missing patch evidence does not prove that no patch exists. Filters below change the event list only.

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