CVE-2026-61598 — djust
CVE-2026-61598 is a CWE-915 vulnerability in djust. A fix is available for djust — see the affected versions and patch details below.
Client mass-assignment of arbitrary view attributes via the default dj-model update_model handler
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-61598.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
Real-World Exposure
djustReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
Description
Impact
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 setattrs 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.
Result: 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" -> bool True), aiding the attacker.
Severity High for apps that hold authorization/ownership/business state in public view attributes (the normal djust pattern) -> 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).
Reproduced: a view with account_id/is_admin/total_price (none bound with dj-model) had all three set via update_model calls.
Patches
Restrict 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.
Workarounds
Set 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.
References
Reproducer + finding writeup retained privately by the maintainer.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | djust | all versions | 1.0.7pip install --upgrade 'djust==1.0.7' |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for djust, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update djust to 1.0.7 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-61598 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
Frequently Asked Questions
Is CVE-2026-61598 in your dependencies?
Find it across PyPI, including transitive dependencies.