CVE-2025-64458
HIGHCVE-2025-64458 is a high-severity (CVSS 7.5) CWE-407 vulnerability in django. O3 Security confirms whether CVE-2025-64458 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Potential denial-of-service vulnerability in HttpResponseRedirect and HttpResponsePermanentRedirect on Windows
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 5.1 before 5.1.14, 4.2 before 4.2.26, and 5.2 before 5.2.8.
NFKC normalization in Python is slow on Windows. As a consequence, django.http.HttpResponseRedirect, django.http.HttpResponsePermanentRedirect, and the shortcut django.shortcuts.redirect were subject to a potential denial-of-service attack via certain inputs with a very large number of Unicode characters.
Earlier, unsupported Django series (such as 5.0.x, 4.1.x, and 3.2.x) were not evaluated and may also be affected.
Django would like to thank Seokchan Yoon for reporting this issue.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | django | ≥ 5.2a1&&< 5.2.8 | 5.2.8 |
| 🐍PyPI | django | ≥ 5.0a1&&< 5.1.14 | 5.1.14 |
| 🐍PyPI | django | all versions | 4.2.26 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for django. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update django to 5.2.8 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-64458 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 pinpoints whether CVE-2025-64458 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2025-64458. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2025-64458 in your dependencies?
O3 detects CVE-2025-64458 across PyPI dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.