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Fencer Vulns
medium 5.3

CVE-2018-7537 json

Django Denial-of-service possibility in truncatechars_html and truncatewords_html template filters

published 2018-03-09 8 y ago modified 2026-06-17 4 mo ago also GHSA-2f9x-5v75-3qv4 , PYSEC-2018-6 , EUVD-2018-0041

cvss
5.3
version 3.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
4.4%
EPSS 4.4% 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. If django.utils.text.Truncator's chars() and words() methods were passed the html=True argument, they were extremely slow to evaluate certain inputs due to a catastrophic backtracking vulnerability in a regular expression. The chars() and words() methods are used to implement the truncatechars_html and truncatewords_html 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-2018-7537

  • 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-2018-7537

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-2019:0265

  • 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-2018-7537

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-2018-7537 updated cvss 5.3

django: Catastrophic backtracking in regular expressions via 'truncatechars_html' and 'truncatewords_html'

  • 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
    +10 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 10 (Newton) python-django, python-django-bash-completion Red Hat OpenStack Platform 11 (Ocata) python-django Red Hat OpenStack Platform 12 (Pike) python-django, python-django-bash-completion Red Hat OpenStack Platform 13 (Queens) python-django, python2-django, python-django-bash-completion 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 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

4.37% 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
>=2.0, <2.0.3
>=1.11, <1.11.11
>=1.8, <1.8.19
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.