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

Severity: medium (CVSS 6.3 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-09-16 · updated 2026-09-30
Weakness: CWE-348

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`.

Affected products

djust-org djust: before 1.0.7

References

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