CVE-2023-36053 is a high-severity (CVSS 7.5) CWE-1333 vulnerability in django. A fix is available for django — see the affected versions and patch details below.
Django has regular expression denial of service vulnerability in EmailValidator/URLValidator
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2023-36053.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2023-36053 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,333 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
django🐍django🐍djangoReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
Description
In Django 3.2 before 3.2.20, 4 before 4.1.10, and 4.2 before 4.2.3, EmailValidator and URLValidator are subject to a potential ReDoS (regular expression denial of service) attack via a very large number of domain name labels of emails and URLs.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | django | ≥ 3.2a1&&< 3.2.20 | 3.2.20pip install --upgrade 'django==3.2.20' |
| 🐍PyPI | django | ≥ 4.0a1&&< 4.1.10 | 4.1.10pip install --upgrade 'django==4.1.10' |
| 🐍PyPI | django | ≥ 4.2a1&&< 4.2.3 | 4.2.3pip install --upgrade 'django==4.2.3' |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for django, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update django to 3.2.20 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-36053 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2023-36053 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2023-36053. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
| Product | Fixed in | Advisory |
|---|---|---|
| Red Hat Ansible Automation Platform 2.4 for RHEL 8 | automation-controller-0:4.4.2-1.el8ap | RHSA-2023:4692 |
| Red Hat Ansible Automation Platform 2.4 for RHEL 8 | python3x-django-0:3.2.20-1.el8ap | RHSA-2023:4693 |
| Red Hat OpenStack Platform 17.1 for RHEL 9 | python-django-0:2.2.24-5.el9ost | RHSA-2024:0212 |
| Red Hat Satellite 6.13 for RHEL 8 | python-django-0:3.2.21-1.el8pc | RHSA-2023:5931 |
| Red Hat Satellite 6.14 for RHEL 8 | python-django-0:3.2.21-1.el8pc | RHSA-2023:6818 |
| RHUI 4 for RHEL 8 | python-django-0:4.2.11-1.el8ui | RHSA-2024:1878 |
Frequently Asked Questions
Is CVE-2023-36053 in your dependencies?
O3 Security finds CVE-2023-36053 across PyPI dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.