# CVE-2026-43912: Vaultwarden: Cross-Org Group Binding Enables Unauthorized Read And Write Access Into Another Organization

> An attacker with admin rights in one organization can bind foreign memberships to gain unauthorized read and write access to another organization's vault data.

- **Severity:** High 8.7 (`CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 11 May 2026
- **Updated:** 12 May 2026
- **Also known as:** GHSA-569v-845w-g82p

## What is CVE-2026-43912?

CVE-2026-43912 is a high-severity missing authorization vulnerability in dani-garcia vaultwarden, published on 11 May 2026. An attacker needs administrator access to exploit it, with no action from the victim.

### Official description

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.

Weakness: CWE-285 (Improper Authorization)

## Which versions are affected by CVE-2026-43912?

It affects 1 product.


Products: Dani-Garcia Vaultwarden.

## How do I fix CVE-2026-43912?

No fix has been published for CVE-2026-43912 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-43912 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-43912 exists.

## Other vulnerabilities in dani-garcia vaultwarden

- [CVE-2024-55225](https://insights.sbomify.com/CVE-2024-55225/): Vaultwarden vulnerable to user impersonation (critical 9.8)
- [CVE-2024-55224](https://insights.sbomify.com/CVE-2024-55224/): Vaultwarden HTML injection vulnerability (critical 9.6)
- [CVE-2024-39924](https://insights.sbomify.com/CVE-2024-39924/): Privilege escalation in n/a (high 8.8)
- [CVE-2026-27802](https://insights.sbomify.com/CVE-2026-27802/): Vaultwarden: Privilege Escalation via Bulk Permission Update to Unauthorized Collections by Manager (high 8.3)
- [CVE-2026-27803](https://insights.sbomify.com/CVE-2026-27803/): Vaultwarden: Collection Management Operations Allowed Without `manage` Verification for Manager Role (high 8.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-43912 and fix it if it is affected.

What it is: CVE-2026-43912 is a high-severity missing authorization vulnerability in dani-garcia vaultwarden, published on 11 May 2026. An attacker needs administrator access to exploit it, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-43912 exists.

Affected product: dani-garcia vaultwarden. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-43912/ (Markdown: https://insights.sbomify.com/CVE-2026-43912/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-43912
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-43912
- OSV: https://osv.dev/vulnerability/CVE-2026-43912

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-43912/
Summaries are generated and may contain mistakes; the official description above is the record.