# CVE-2026-61589: djust: WebSocket/runtime reconstructed request omits the client Host, causing host/subdomain TenantResolvers to misresolve the tenant on the live path

> Attackers can access cross-tenant data in djust when STRICT_MODE is disabled due to missing Host header in WebSocket requests.

- **Severity:** Medium 6.3 (`CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 16 Sep 2026
- **Updated:** 17 Sep 2026
- **Also known as:** GHSA-v9rj-xjfv-xj9r, PYSEC-2026-4046

## What is CVE-2026-61589?

CVE-2026-61589 is a medium-severity vulnerability in djust-org djust, published on 16 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

djust provides Phoenix LiveView-style reactive server-side rendering for Django with Rust-powered performance. Prior to version 1.0.7, the WebSocket `handle_mount` and `ViewRuntime._build_request` rebuild an `HttpRequest` via `RequestFactory().get(...)` with no `HTTP_HOST`, so `request.get_host()` defaulted to `"testserver"` on the live path. Host/subdomain/domain `TenantResolver`s then misresolved the tenant — `None` on the live path while the HTTP path resolved correctly. With `STRICT_MODE=False` the tenant-scoped managers returned unscoped rows (cross-tenant disclosure); with the default they returned an empty queryset (broken tenancy). This is fixed in djust 1.0.7. The handshake Host is extracted from the ASGI scope, validated against `ALLOWED_HOSTS` (the same logic as the CSWSH Origin gate, parsed with Django's `split_domain_port` so malformed Hosts are rejected at the boundary), and propagated — with the TLS scheme — into the reconstructed request, so live-path tenant resolution matches HTTP exactly. There is no known workaround on the live path short of upgrading. Users are most exposed when combined with `STRICT_MODE=False`.

Weakness: CWE-639 (Authorization Bypass Through User-Controlled Key), CWE-348 (Use of Less Trusted Source)

## Which versions are affected by CVE-2026-61589?

3 open source packages ship an affected version, including djust.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `djust` | PyPI | All versions | 1.0.7 |
| `djust` | PyPI | All versions | 1.0.7 |
| `djust` | PyPI | All versions | 1.0.7 |

## How do I fix CVE-2026-61589?

Upgrade djust to 1.0.7 or later.

## Is CVE-2026-61589 being exploited?

There is no known exploitation of CVE-2026-61589 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-61589 and fix it if it is affected.

What it is: CVE-2026-61589 is a medium-severity vulnerability in djust-org djust, published on 16 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-61589 in the wild and no public exploit code.

Affected packages and fixed versions:
- djust (PyPI): affected all versions; fixed in 1.0.7
- djust (PyPI): affected all versions; fixed in 1.0.7
- djust (PyPI): affected all versions; fixed in 1.0.7

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-2026-61589/ (Markdown: https://insights.sbomify.com/CVE-2026-61589/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-61589
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-61589
- OSV: https://osv.dev/vulnerability/CVE-2026-61589

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-61589/
Summaries are generated and may contain mistakes; the official description above is the record.