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Fencer Vulns
high 8.2

CVE-2026-55571 json

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

published 2026-08-25 2 mo ago modified 2026-09-10 1 mo ago also GHSA-xx4j-w367-7247 , PYSEC-2026-3829 , EUVD-2026-65600

cvss
8.2
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 43%
public exploits
0
none known

Summary

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.

Patch / fix

  • pypi djust 1.0.4

CISA SSVC

Exploitation
Proof of concept is public
Automatable
yes
Technical impact
partial
Assessed
2 mo ago

Exploit prediction

0.51% chance of exploitation in the next 30 days, higher than 43% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/djust-org/djust/security/advisories/GHSA-xx4j-w367-7247 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 8.2 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:N
OSV 3.1 8.2 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:N
GitHub 3.1 8.2 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:H/A:N

Affected packages

ecosystem package affected fixed in
pypi djust
<1.0.4
1.0.4

Affected products

  • djust-org djust

Classification

Weakness
  • CWE-285 Improper Authorization
  • CWE-306 Missing Authentication for Critical Functionality

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.