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Fencer Vulns
high 7.4

CVE-2020-35681 json

Django Channels leakage of session identifiers using legacy AsgiHandler

published 2021-02-22 5 y ago modified 2026-06-17 4 mo ago also GHSA-v542-8q9x-cffc , PYSEC-2021-113 , EUVD-2021-0041

cvss
7.4
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
2.7%
EPSS 2.7% chance of exploitation in 30 days, percentile 85%
public exploits
0
none known

Summary

Django Channels 3.x before 3.0.3 allows remote attackers to obtain sensitive information from a different request scope. The legacy channels.http.AsgiHandler class, used for handling HTTP type requests in an ASGI environment prior to Django 3.0, did not correctly separate request scopes in Channels 3.0. In many cases this would result in a crash but, with correct timing, responses could be sent to the wrong client, resulting in potential leakage of session identifiers and other sensitive data. Note that this affects only the legacy Channels provided class, and not Django's similar ASGIHandler, available from Django 3.0.

Patch / fix

  • pypi channels 3.0.3
  • djangoproject channels 3.0.3
  • python-django-channels Debian 14, Debian 13, Debian 12 3.0.3-1

debian advisories DEBIAN-CVE-2020-35681

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2020-35681 updated cvss 7.4

django-channels: potential leakage of session identifiers using legacy AsgiHandler

  • Red Hat Update Infrastructure 3 for Cloud Providers python-django
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

2.66% chance of exploitation in the next 30 days, higher than 85% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • channels.readthedocs.io https://channels.readthedocs.io/en/stable/releases/3.0.3.html referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.1 7.4 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:H
NVD 2.0 5.8 AV:N/AC:M/Au:N/C:P/I:N/A:P
GitHub 3.1 7.4 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:H

Affected packages

ecosystem package affected fixed in
pypi channels
>=3.0.0, <3.0.3
3.0.3

Classification

Weakness
  • CWE-200 Exposure of Sensitive Information to an Unauthorized Actor

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.