GHSA-qmf9-6jqf-j8fq is a high-severity (CVSS 7.5) CWE-770 vulnerability in django. EPSS puts its 30-day exploitation probability at 49.8% (99th percentile). A fix is available for django — see the affected versions and patch details below.
Django potential denial of service vulnerability in UsernameField on Windows
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
GHSA-qmf9-6jqf-j8fq plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE sits: patch-first territory.
Where this sits among everything scored
Of 377,636 CVEs with a current EPSS score, this one falls in the 10–50% 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
An issue was discovered in Django 3.2 before 3.2.23, 4.1 before 4.1.13, and 4.2 before 4.2.7. The NFKC normalization is slow on Windows. As a consequence, django.contrib.auth.forms.UsernameField is subject to a potential DoS (denial of service) attack via certain inputs with a very large number of Unicode characters.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | django | ≥ 3.2a1&&< 3.2.23 | 3.2.23pip install --upgrade 'django==3.2.23' |
| 🐍PyPI | django | ≥ 4.1a1&&< 4.1.13 | 4.1.13pip install --upgrade 'django==4.1.13' |
| 🐍PyPI | django | ≥ 4.2a1&&< 4.2.7 | 4.2.7pip install --upgrade 'django==4.2.7' |
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 3.2.23 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-qmf9-6jqf-j8fq 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 GHSA-qmf9-6jqf-j8fq can be triaged on real exposure rather than presence alone.
Tailored to GHSA-qmf9-6jqf-j8fq. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-qmf9-6jqf-j8fq in your dependencies?
O3 Security finds GHSA-qmf9-6jqf-j8fq across PyPI dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.