CVE-2026-43912

Vaultwarden is a Bitwarden-compatible server written in Rust. Prior to 1.35.5, Vaultwarden does not enforce that a groups_users.users_organizations_uuid entry belongs to the same organization as groups.groups_uuid, or a collections_groups.collections_uuid entry belongs to the same organization as collections_groups.groups_uuid. Multiple organization group-management endpoints accept arbitrary MembershipId and CollectionId values and persist them directly without verifying org consistency. This lets an attacker who is Admin in Organization A, and only a low-privileged member in Organization B bind their Org B membership UUID into an Org A group, then use that foreign group relationship to gain unauthorized access to Org B vault data. With an accessAll=true Org A group, the attacker can make /api/sync and /api/ciphers enumerate Org B ciphers. Once those unauthorized sync results reveal Org B collection IDs, the attacker can also bind those foreign collection IDs to the Org A group and turn the same flaw into write access over Org B items. This vulnerability is fixed in 1.35.5.

Affected products

Vaultwarden

Dani-garcia Vaultwarden

< 1.35.5

Fix

Available

CVSS 3.1

8.7 HIGH

EPSS

0.3% (21th percentile)

Weakness

CWE-285

NVD status

Analyzed

Published

2026-05-11

No exploit for CVE-2026-43912 has been indexed yet. Our index is built from live traffic and upstream syncs, so this page can only say what it knows — not that no exploit exists.