{"id":"GHSA-cc7c-9jff-58wj","summary":"djust: Client mass-assignment of arbitrary view attributes via the default dj-model update_model handler","details":"### Impact\n`djust.mixins.model_binding.ModelBindingMixin` provides a default `update_model` event handler and is part of the **LiveView base MRO**, so every LiveView exposes it. It `setattr`s a view attribute whose **name is client-supplied** (`field`), gated only by: reject `_`-prefixed names; reject a **14-entry denylist** of framework internals (`FORBIDDEN_MODEL_FIELDS`); optional `allowed_model_fields` which **defaults to None = allow all**; and `hasattr` existence.\n\nResult: a client can set **any public, existing view attribute — not just the fields actually bound with `dj-model=` in the rendered template**. The denylist covers framework plumbing but nothing about developer business/authz state, and the allowlist is opt-in (off by default). A developer who binds one `dj-model=\"search\"` input and also keeps `self.account_id` / `self.is_admin` / `self.total_price` as view state does not realize a client can set ALL of them via `{type:event, event:\"update_model\", params:{field, value}}` over the WebSocket. Type coercion matches the target attribute's type (so `\"true\"` -\u003e bool True), aiding the attacker.\n\n**Severity High** for apps that hold authorization/ownership/business state in public view attributes (the normal djust pattern) -\u003e state tampering / IDOR / authz-flag manipulation; Low otherwise. Default-on across every LiveView. For a public (no-login) view an anonymous client can mass-assign; for an authenticated view a logged-in user can tamper their own session's view state (the IDOR/authz vector when downstream handlers act on it without re-authorizing).\n\nReproduced: a view with `account_id/is_admin/total_price` (none bound with dj-model) had all three set via `update_model` calls.\n\n### Patches\nRestrict the default handler to fields actually exposed via `dj-model=`: have the template renderer record the bound-field set per render and reject any `field` outside it (preferred, secure + zero-config); or make `allowed_model_fields` fail-closed (required). Keep `FORBIDDEN_MODEL_FIELDS` only as defense-in-depth. Add a regression that a non-`dj-model` public attribute (e.g. `is_admin`) is rejected while a bound field still updates.\n\n### Workarounds\nSet `allowed_model_fields` explicitly on every view using dj-model (or subclassing LiveView) to the minimal list of bindable fields; do not keep authorization/ownership state in public view attributes that share the view with dj-model bindings.\n\n### References\nReproducer + finding writeup retained privately by the maintainer.","aliases":["CVE-2026-61598"],"modified":"2026-09-16T14:15:52.778079318Z","published":"2026-09-16T13:55:48Z","database_specific":{"github_reviewed":true,"github_reviewed_at":"2026-09-16T13:55:48Z","nvd_published_at":null,"cwe_ids":["CWE-915"],"severity":"HIGH"},"references":[{"type":"WEB","url":"https://github.com/djust-org/djust/security/advisories/GHSA-cc7c-9jff-58wj"},{"type":"PACKAGE","url":"https://github.com/djust-org/djust"},{"type":"WEB","url":"https://github.com/djust-org/djust/releases/tag/v1.0.7"}],"affected":[{"package":{"name":"djust","ecosystem":"PyPI","purl":"pkg:pypi/djust"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.0.7"}]}],"versions":["0.1.0","0.1.2","0.1.3","0.1.4","0.1.5","0.1.6","0.1.7","0.1.8","0.1.9","0.2.0","0.2.1","0.2.2","0.3.0","0.3.1","0.3.2","0.3.4","0.3.5","0.3.6","0.3.7","0.3.8","0.4.0","0.4.1","0.4.2","0.4.3","0.4.4","0.9.0","0.9.1","0.9.2","0.9.4","0.9.5","0.9.6","0.9.7","1.0.0","1.0.0rc1","1.0.0rc10","1.0.0rc11","1.0.0rc12","1.0.0rc13","1.0.0rc14","1.0.0rc15","1.0.0rc16","1.0.0rc17","1.0.0rc18","1.0.0rc2","1.0.0rc3","1.0.0rc4","1.0.0rc6","1.0.0rc7","1.0.0rc8","1.0.0rc9","1.0.1","1.0.1rc1","1.0.2","1.0.2rc1","1.0.2rc2","1.0.2rc3","1.0.3","1.0.3rc1","1.0.3rc2","1.0.4","1.0.4rc1","1.0.5","1.0.5rc1","1.0.5rc2","1.0.5rc3","1.0.5rc4","1.0.5rc5","1.0.6","1.0.6rc1","1.0.6rc2","1.0.6rc3","1.0.7rc1"],"database_specific":{"source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/09/GHSA-cc7c-9jff-58wj/GHSA-cc7c-9jff-58wj.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N"}]}