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

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

8.2 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:N

EPSS

• CVE-2026-55571: 0.51% estimated exploitation activity in the next 30 days; percentile 43.21 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Impact djust's LiveViewConsumer mounts a LiveView over a WebSocket. When a view is gated (loginrequired / permissionrequired, or an onmount hook that returns a redirect) and the connecting user is not authorized, the consumer sent the client a {"type":"navigate","to":...} redirect frame and then returned — without closing the socket and without clearing self.viewinstance. Only the PermissionDenied branch closed the connection (close(4403)). A real browser obeys the navigate frame and leaves, hiding the problem. A raw WebSocket client that ignores the redirect keeps an open, mounted socket. Because handleevent did not re-check authentication/authorization after mount, that client could then send {"type":"event", ...} frames and invoke any @eventhandler method on the gated view with no authenticated session — an authentication bypass on the live mutation path. Who is affected: apps that expose LiveViews gated by loginrequired / permissionrequired / a redirecting onmount hook, where the…

Published by the source

25 Aug 2026, 16:06 UTC

Last modified by the source

25 Aug 2026, 16:06 UTC

Source last checked

26 Oct 2026, 13:50 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-xx4j-w367-7247

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# Patch Next advisory brief: CVE-2026-55571

Advisory: 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
IDs: CVE-2026-55571, GHSA-xx4j-w367-7247
Record: https://patchnext.com/advisories/cve-2026-55571 (revision 1, source checked 26 Oct 2026, 13:50 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 8.2)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: djust 1.0.4. A vendor fix does not mean a deployment is fixed.

## Affected components
- PyPI djust: affected < 1.0.4; fixed in 1.0.4

## Suggested inspection (read-only)
- `python -m pip show djust`: prints the installed version. Run with the environment that serves production active.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on djust.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-xx4j-w367-7247 (GitHub-reviewed advisory GHSA-xx4j-w367-7247 lists affected ranges: PyPI djust >=0 <1.0.4)

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