Auth bypass in Bitwarden Server
CVE-2026-43638
Bitwarden Server prior to v2026.4.1 contains a missing authorization vulnerability that allows any authenticated user to write ciphers into an arbitrary organization via `POST /ciphers/import-organization` by submitting an empty `collectio…
Vulnerability class: Broken Access Control
EPSS: 0.000 (8.9th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N.
Affected products
- Bitwarden Server — versions 0
Weakness classification (CWE)
References
- disclosure@vulncheck.com (Exploit, technical-description, Third Party Advisory, exploit)
- disclosure@vulncheck.com (release-notes, Release Notes)
- disclosure@vulncheck.com (issue-tracking, Patch, Issue Tracking)
- disclosure@vulncheck.com (Patch, patch)
- disclosure@vulncheck.com (Third Party Advisory, third-party-advisory)
Frequently asked questions
- What is CVE-2026-43638?
- CVE-2026-43638 is a medium-severity vulnerability in Bitwarden Server, classified under Missing Authorization. CVSS score: 5.4/10. Published 2026-05-11.
- How severe is CVE-2026-43638?
- Medium severity. CVSS v3 base score is 5.4 out of 10.