Vulnerability · Published Jun 3, 2026 · Assigned by DSF
CVE-2026-8404Potential exposure of private data via case-sensitive Cache-Control directives in UpdateCacheMiddleware
Low 3.1
In plain English
A low-severity security flaw in Django from djangoproject. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 20% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
An issue was discovered in Django 5.2 before 5.2.15 and 6.0 before 6.0.6. `django.middleware.cache.UpdateCacheMiddleware` in Django does not match `Cache-Control` response directives case-insensitively, which allows remote attackers to read responses that were incorrectly cached because their `Cache-Control` directives used uppercase or mixed-case 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 Ahmed Badawe for reporting this issue.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine:v3.24 | py3-django | 5.2.15-r0 | ALPINE-CVE-2026-8404 |
| Debian:12 | python-django | no fix listed | DEBIAN-CVE-2026-8404 |
| Debian:13 | python-django | no fix listed | DEBIAN-CVE-2026-8404 |
| Debian:14 | python-django | 3:5.2.15-1 | DEBIAN-CVE-2026-8404 |
| PyPI | django | 5.2.15 | GHSA-8cjm-8mp7-r2xf |
| PyPI | django | 5.2.15, 6.0.6 | PYSEC-2026-201 |
| PyPI | django | 6.0.6 | GHSA-8cjm-8mp7-r2xf |
| Ubuntu:22.04:LTS | python-django | 2:3.2.12-2ubuntu1.29 | UBUNTU-CVE-2026-8404 |
| Ubuntu:22.04:LTS | python-django | 2:3.2.12-2ubuntu1.29 | USN-8848-1 |
| Ubuntu:24.04:LTS | python-django | 3:4.2.11-1ubuntu1.18 | USN-8848-1 |
| Ubuntu:24.04:LTS | python-django | 3:4.2.11-1ubuntu1.18 | UBUNTU-CVE-2026-8404 |
| Ubuntu:25.10 | python-django | no fix listed | UBUNTU-CVE-2026-8404 |
| Ubuntu:26.04:LTS | python-django | 3:5.2.9-0ubuntu4.3 | USN-8848-1 |
| Ubuntu:26.04:LTS | python-django | 3:5.2.9-0ubuntu4.3 | UBUNTU-CVE-2026-8404 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| djangoproject | Django | 6.0 – before 6.0.65.2 – before 5.2.15 |
Weakness: CWE-178 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:N/A:N
References
- Django security archive vendor-advisory
- Django releases announcements mailing-list
- Django security releases issued: 6.0.6 and 5.2.15 vendor-advisory