# CVE-2026-43640: Bitwarden Server < 2026.4.1 Authentication Bypass via SCIM API Key

> Authenticated users with SCIM privileges can bypass master-password re-authentication to retrieve or rotate organization SCIM API keys.

- **Severity:** High 8.6 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 11 May 2026
- **Updated:** 14 Jul 2026
- **Also known as:** GHSA-6736-x63f-c628

## What is CVE-2026-43640?

CVE-2026-43640 is a high-severity authentication bypass vulnerability in bitwarden server, published on 11 May 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

Bitwarden Server prior to v2026.4.1 does not require master-password re-authentication when retrieving or rotating an organization's SCIM API key, allowing an authenticated user with SCIM management privileges to obtain the key using only a valid session.

Weakness: CWE-303 (Incorrect Implementation of Authentication Algorithm)

## Which versions are affected by CVE-2026-43640?

It affects 1 product.


Products: Bitwarden Server.

## How do I fix CVE-2026-43640?

No fix has been published for CVE-2026-43640 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-43640 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-43640 exists.

## Other vulnerabilities in bitwarden server

- [CVE-2026-60104](https://insights.sbomify.com/CVE-2026-60104/): Bitwarden Server < 2026.6.0 Authorization Bypass via Admin Auth Request (critical 9.3)
- [CVE-2026-43639](https://insights.sbomify.com/CVE-2026-43639/): Bitwarden Server < 2026.4.0 Missing Authorization via Provider Clients (high 8.9)
- [CVE-2020-15879](https://insights.sbomify.com/CVE-2020-15879/): Server-side request forgery in n/a (high 7.5)
- [CVE-2019-19766](https://insights.sbomify.com/CVE-2019-19766/): Weak cryptography in n/a (high 7.5)
- [CVE-2026-57520](https://insights.sbomify.com/CVE-2026-57520/): Bitwarden Server < 2026.5.0 Privilege Escalation via Bulk User Remove Endpoint (high 7.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-43640 and fix it if it is affected.

What it is: CVE-2026-43640 is a high-severity authentication bypass vulnerability in bitwarden server, published on 11 May 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-43640 exists.

Affected product: bitwarden server. 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-2026-43640/ (Markdown: https://insights.sbomify.com/CVE-2026-43640/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-43640
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-43640
- OSV: https://osv.dev/vulnerability/CVE-2026-43640

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-43640/
Summaries are generated and may contain mistakes; the official description above is the record.