Auth bypass in Bitwarden Server
CVE-2026-57520
Bitwarden Server before 2026.5.0 contains a privilege escalation vulnerability that allows authenticated Custom users with ManageUsers permission to remove Admin accounts from an organization by exploiting a missing role hierarchy check in the bulk user-remove endpoint. Attackers can supply Admin organization-user IDs in a bulk DELETE request to bypass the guard enforced on the single-user removal path, effectively removing one or more Admin accounts from an organization.
Vulnerability class: Broken Access Control
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.1 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:L.
EPSS exploit prediction
EPSS: 0.006 (49.2th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 49th percentile — 49.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.006 · newest: 0.006 · change: 0.000
Affected products
- Bitwarden Server — versions 0
Weakness classification (CWE)
References
- sanjokkarki.com.np/blog/bitwarden-bulk-remove-admin (Exploit, technical-description, Patch, Third Party Advisory, exploit)
- github.com/bitwarden/server/releases/tag/v2026.5.0 (release-notes, Release Notes)
- github.com/bitwarden/server/pull/7526 (issue-tracking, Issue Tracking)
- github.com/bitwarden/server/commit/901bb67157c0f80d369c40b76742fdf7623da4e4 (Patch, patch)
- www.vulncheck.com/advisories/bitwarden-server-privilege-escalation-via-bulk-use… (Third Party Advisory, third-party-advisory)
Frequently asked questions
- What is CVE-2026-57520?
- CVE-2026-57520 is a high-severity vulnerability in Bitwarden Server, classified under Missing Authorization. CVSS score: 7.1/10. Published 2026-06-25.
- How severe is CVE-2026-57520?
- High severity. CVSS v3 base score is 7.1 out of 10.