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DjangoFramework / library · Djangoproject

CVE-2025-64458

HIGH · 7.5 CVSS v3.1 Published 2025-11-05
Fix available
A fix is available. Upgrade to 4.2.26 / 5.1.14 or later.
See remediation →
84/100
Remediation priority · High
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

A denial-of-service vulnerability in Django's redirect functions (HttpResponseRedirect, HttpResponsePermanentRedirect, and django.shortcuts.redirect) allows attackers to send inputs with very large numbers of Unicode characters, which triggers slow NFKC normalization on Windows, causing excessive server resource consumption.

MitigationUpgrade Django to versions 5.1.14, 4.2.26, or 5.2.8 or later to receive the patch. If immediate upgrade is not feasible, consider rate-limiting or input validation on redirect endpoints.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
DjangoFramework / library
Affected:>= 4.2, < 4.2.26>= 5.1, < 5.1.14>= 5.2, < 5.2.8

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check installed Django version
    Run 'python -c "import django; print(django.get_version())"' or check your requirements.txt/environment files
    Affected if Version is >= 4.2 and < 4.2.26, OR >= 5.1 and < 5.1.14, OR >= 5.2 and < 5.2.8
  2. Confirm operating system is Windows
    Run 'python -c "import platform; print(platform.system())"' or check server OS
    Affected if Running on Windows (Linux/macOS are not affected by this specific vulnerability)
  3. Identify if redirect-enabled endpoints exist
    Search codebase for HttpResponseRedirect, HttpResponsePermanentRedirect, or django.shortcuts.redirect usage in views, and check if they accept user-supplied input
    Affected if Application uses redirect functions that accept user-controlled URLs or paths as input
  4. Test for Unicode redirect input handling
    If redirect endpoints exist that accept user input, send a request with a very large Unicode string (e.g., thousands of NFKC-normalizable characters) and monitor server response time and CPU usage
    Affected if Server response becomes significantly slower or CPU usage spikes when processing large Unicode inputs to redirect functions

You are affected if running a vulnerable Django version (4.2 to <4.2.26, 5.1 to <5.1.14, or 5.2 to <5.2.8) on Windows with redirect endpoints that accept large Unicode user input.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 4.2.26 / 5.1.14 / 5.2.8 or later
Fixed in 4.2.265.1.145.2.8
Interim mitigation

Upgrade Django to versions 5.1.14, 4.2.26, or 5.2.8 or later to receive the patch. If immediate upgrade is not feasible, consider rate-limiting or input validation on redirect endpoints.

Recommended fix High confidence

Django 4.2.26, 5.1.14, or 5.2.8 (depending on your current series)

  1. 1. Identify the currently installed Django version by running `pip show django` or checking your requirements file
  2. 2. Determine which Django series you are currently using (4.2.x, 5.1.x, or 5.2.x)
  3. 3. Upgrade Django to the appropriate fixed version based on your current series: for 4.2.x upgrade to 4.2.26, for 5.1.x upgrade to 5.1.14, for 5.2.x upgrade to 5.2.8
  4. 4. Run `pip install --upgrade Django==<fixed_version>` replacing <fixed_version> with the appropriate version from step 3
  5. 5. After upgrading, run your test suite to verify the application still functions correctly
  6. 6. If running on Windows, verify that the redirect functions now handle large Unicode inputs without excessive delay
Caveat No breaking changes expected from this security fix; this is a performance optimization patch

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Django Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing4.0 h
  • Review / QA2.0 h
12.0 hours of engineering $2,080
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2025-64458 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data