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Fencer Vulns
medium 5.3

CVE-2018-7536 json

Django denial-of-service possibility in urlize and urlizetrunc template filters

published 2018-03-09 8 y ago modified 2026-06-17 4 mo ago also GHSA-r28v-mw67-m5p9 , PYSEC-2018-5 , EUVD-2018-0040

cvss
5.3
version 3.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
4.6%
EPSS 4.6% chance of exploitation in 30 days, percentile 91%
public exploits
0
none known

Summary

An issue was discovered in Django 2.0 before 2.0.3, 1.11 before 1.11.11, and 1.8 before 1.8.19. The django.utils.html.urlize() function was extremely slow to evaluate certain inputs due to catastrophic backtracking vulnerabilities in two regular expressions (only one regular expression for Django 1.8.x). The urlize() function is used to implement the urlize and urlizetrunc template filters, which were thus vulnerable.

Patch / fix

  • pypi django 1.8.19, 1.11.11, 2.0.3
  • djangoproject django 1.8.19, 1.11.11, 2.0.3
  • python-django Debian 14, Debian 13, Debian 12 1:1.11.11-1

debian advisories DEBIAN-CVE-2018-7536

  • python-django Ubuntu 14.04 LTS 1.6.11-0ubuntu1.2
  • python-django Ubuntu 16.04 LTS 1.8.7-1ubuntu5.6

ubuntu advisories UBUNTU-CVE-2018-7536

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • v8 satellite capsule 6.4 1:3.14.5.10-19.el7sat
  • tfm satellite capsule 6.4, satellite 6.4 4.0-3.el7sat
  • kobo satellite capsule 6.4, satellite 6.4 0.5.1-1.el7sat
  • pulp satellite capsule 6.4, satellite 6.4 2.16.4.1-1.el7sat
  • gofer satellite capsule 6.4, satellite 6.4 2.12.1-1.el7sat
  • ostree satellite capsule 6.4, satellite 6.4 2017.1-2.atomic.el7
  • SOAPpy satellite capsule 6.4, satellite 6.4 0.11.6-17.el7
  • foreman satellite capsule 6.4, satellite 6.4 1.18.0.37-1.el7sat

red hat advisories RHSA-2018:2927RHSA-2019:0051RHSA-2019:0265RHSA-2019:0082

  • python-Django Enterprise Storage 5 1.6.11-6.5.1
  • python-Django Enterprise Storage 4 1.6.11-5.5.1
  • python-Django OpenStack Cloud 6 1.8.19-3.6.1
  • python-Django OpenStack Cloud 7 1.8.19-3.4.1

suse advisories SUSE-SU-2018:1830-1SUSE-SU-2018:1828-1SUSE-SU-2018:1102-1SUSE-SU-2018:0973-1

  • python-Django5 openSUSE Tumbleweed 5.2.16-1.1
  • python-Django openSUSE Tumbleweed 5.2.16-1.1
  • python-Django4 openSUSE Tumbleweed 4.2.30-4.1
  • python-Django6 openSUSE Tumbleweed 6.0-1.1
  • python-Django4 openSUSE Tumbleweed 4.2.14-1.1
  • python-Django openSUSE Tumbleweed 3.2.7-2.3
  • python-Django openSUSE Tumbleweed 4.2.11-2.1
  • python-Django Package Hub 12 SP1 1.11.15-2.1

opensuse advisories openSUSE-SU-2026:11270-1openSUSE-SU-2026:11248-1openSUSE-SU-2026:11235-1openSUSE-SU-2026:10005-1openSUSE-SU-2024:14208-1openSUSE-SU-2024:11205-1

  • py-django Alpine 3.10, Alpine 3.9, Alpine 3.8 +2 more 1.11.11-r0
  • py-django Alpine 3.5, Alpine 3.4 1.8.19-r0
  • py3-django Alpine 3.24, Alpine 3.23, Alpine 3.22 +11 more 1.11.11-r0

alpine advisories ALPINE-CVE-2018-7536

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • python-django Arch Linux 1.11.11-1

arch linux advisories AVG-649

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-2018-7536 updated cvss 5.3

django: Catastrophic backtracking in regular expressions via 'urlize' and 'urlizetrunc'

  • Red Hat Ceph Storage 1.3 python-django Red Hat Ceph Storage 2 python-django, python-django-bash-completion Red Hat Ceph Storage 3 python-django, python-django-bash-completion Red Hat Enterprise Linux OpenStack Platform 6 (Juno) python-django Red Hat Enterprise Linux OpenStack Platform 7 (Kilo) python-django, python-django-bash-completion Red Hat Enterprise Linux OpenStack Platform 7 (Kilo) Operational Tools python-django, python-django-bash-completion
    +5 more products
    Red Hat OpenStack Platform 8 (Liberty) python-django, python-django-bash-completion Red Hat OpenStack Platform 8 (Liberty) Operational Tools python-django, python-django-bash-completion Red Hat OpenStack Platform 9 (Mitaka) python-django, python-django-bash-completion Red Hat OpenStack Platform 9 (Mitaka) Operational Tools python-django, python-django-bash-completion Red Hat OpenStack Platform 11 (Ocata) python-django
    affected: no fix planned “Will not fix”
  • Red Hat OpenStack Platform 12 (Pike) python-django, python-django-bash-completion
    affected: no fix available
  • Red Hat Storage Console 2 python-django Red Hat Subscription Asset Manager Django
    affected: no fix planned “Will not fix”
  • Red Hat Gluster 3.4 Web Administration Node Agent on RHEL-7 tendrl-selinux 1.5.4-3.el7rhgs, tendrl-commons 1.6.3-15.el7rhgs, tendrl-node-agent 1.6.3-15.el7rhgs, tendrl-collectd-selinux 1.5.4-3.el7rhgs Red Hat Gluster 3.4 Web Administration on RHEL-7 tendrl-api 1.6.3-10.el7rhgs, graphite-web 1.1.4-1.el7rhgs, python-scandir 1.3-1.el7rhgs, python-carbon 1.1.4-1.el7rhgs, carbon-selinux 1.5.4-3.el7rhgs, python-whisper 1.1.4-1.el7rhgs, +13 more
    fixed: vendor fix RHSA-2019:0265
  • Red Hat OpenStack Platform 10.0 python-django 1.8.19-1.el7ost, python-django-bash-completion 1.8.19-1.el7ost
    fixed: vendor fix RHSA-2019:0051
  • Red Hat OpenStack Platform 13.0 python-django 1.11.11-1.el7ost, python2-django 1.11.11-1.el7ost, python-django-bash-completion 1.11.11-1.el7ost
    fixed: vendor fix RHSA-2019:0082
  • Red Hat Satellite 6.4 tfm 4.0-3.el7sat, kobo 0.5.1-1.el7sat, SOAPpy 0.11.6-17.el7, candlepin 2.4.8-1.el7, gofer 2.12.1-1.el7sat, liquibase 3.1.0-1.el7, +383 more Red Hat Satellite Capsule 6.4 tfm 4.0-3.el7sat, kobo 0.5.1-1.el7sat, SOAPpy 0.11.6-17.el7, gofer 2.12.1-1.el7sat, katello 3.7.0-8.el7sat, pulp 2.16.4.1-1.el7sat, +217 more
    fixed: vendor fix RHSA-2018:2927

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

4.55% chance of exploitation in the next 30 days, higher than 91% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.0 5.3 CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
NVD 2.0 5.0 AV:N/AC:L/Au:N/C:N/I:N/A:P
GitHub 3.0 5.3 CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Affected packages

ecosystem package affected fixed in
pypi django
>=2.0a1, <2.0.3
>=1.11a1, <1.11.11
>=1.8a1, <1.8.19
>=1.8, <1.8.19
>=1.11, <1.11.11
>=2.0, <2.0.3
2.0.3
1.11.11
1.8.19

Classification

Weakness
  • CWE-185 Incorrect Regular Expression
Technology feeds

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.