CVE-2026-61595: djust: Multi-tenant isolation fails open on the WebSocket/SSE path, disclosing other tenants' data

Severity: high (CVSS 7.7 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% 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-636

Description

djust provides Phoenix LiveView-style reactive server-side rendering for Django with Rust-powered performance. Prior to version 1.0.7, `djust.tenants` isolation was enforced only on the HTTP path. The current tenant was stored in `threading.local()` and set exclusively by the HTTP-only `TenantMiddleware`, so on the live (WebSocket/SSE) path `get_current_tenant()` was always `None` during mount and every event handler — and the tenant-aware `QuerySet` manager failed OPEN (returned the unfiltered queryset, ignoring `STRICT_MODE`), disclosing every tenant's rows to whoever held the socket. `threading.local` was additionally shared across connections on the `sync_to_async` executor thread. This issue is fixed in djust 1.0.7. Tenant storage moved to a `contextvars.ContextVar` (per async task); the resolved tenant is bound around WS/SSE mount and every dispatch; both managers scope the base queryset once and fail CLOSED (`.none()` under the default `STRICT_MODE`); and system check S006 warns when `STRICT_MODE=False`. No known workarounds are available on the live path.

Affected products

djust-org djust: before 1.0.7

References

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