CVE-2026-48587 — django
Fix: django/django@1721035CVE-2026-48587 is a CWE-1023 vulnerability in django. A fix is available for django — see the affected versions and patch details below.
Potential exposure of private data via whitespace padding in Vary header
Exploitation Status
No confirmed exploitation observed yet
- 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-2026-48587.
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.
Real-World Exposure
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 5.2 before 5.2.15 and 6.0 before 6.0.6.
django.utils.cache.has_vary_header() in Django does not strip leading or trailing whitespace from Vary response header values before comparison, which allows remote attackers to read cached responses via requests to URLs whose responses contain whitespace-padded Vary header values.
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 Navid Rezazadeh for reporting this issue.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | django | all versions | 5.2.15pip install --upgrade 'django==5.2.15' |
| 🐍PyPI | django | ≥ 6.0.0&&< 6.0.6 | 6.0.6pip install --upgrade 'django==6.0.6' |
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 5.2.15 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-48587 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-2026-48587 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2026-48587. 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-2026-48587 in your dependencies?
O3 Security finds CVE-2026-48587 across PyPI dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.