CVE-2026-55571: djust authentication bypass: a login_required / on_mount LiveView mount redirect does not close the WebSocket, allowing an unauthenticated client to dispatch event-handler calls

Severity: high (CVSS 8.2 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.5% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-08-25 · updated 2026-09-09
Weakness: CWE-285

Description

djust provides Phoenix LiveView-style reactive server-side rendering for Django with Rust-powered performance. Prior to 1.0.4, LiveViewConsumer.handle_mount sends a `{"type":"navigate","to":...}` frame when login_required, permission_required, or a redirecting on_mount hook denies a LiveView mount, but returns without closing the WebSocket or clearing self.view_instance. A browser follows the redirect, but a raw WebSocket client can ignore it and retain the mounted socket. Because LiveViewConsumer.handle_event does not recheck authentication or authorization, the client can send `{"type":"event",...}` frames that invoke @event_handler methods without an authenticated session, including through handle_live_redirect_mount, enabling unauthorized sensitive reads or mutations. This issue is fixed in version 1.0.4.

Affected products

djust-org djust: before 1.0.4

References

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