GHSA-8cjm-8mp7-r2xf BIT-django-2026-8404 CVE-2026-8404 PYSEC-2026-201

Django: UpdateCacheMiddleware may disclose cached responses due to case-sensitive Cache-Control handling

Medium PyPI

Severity: 0.0 / 10; Medium · CVSS 4.0
Exploit chance (EPSS): 0.27%; Chance of exploitation in the next 30 days. Higher than 19.82% of scored vulnerabilities.
Known exploited: No; Not in CISA's catalog
Weakness: CWE-178 Improper Handling of Case Sensitivity
Fix: 5.2.15; Upgrade django to this version or later

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 versions

PyPI

Package	Vulnerable	Fixed in
django	`< 5.2.15`	`5.2.15`
django	`>= 6.0.0, < 6.0.6`	`6.0.6`
django	`>= 5.2, < 5.2.15` `>= 6.0, < 6.0.6`	`5.2.15` `6.0.6`

How to fix

Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.

django PyPI → `5.2.15`

pip

pip install --upgrade "django>=5.2.15"

poetry

poetry add "django>=5.2.15"

uv

uv add "django>=5.2.15"

Severity breakdown

CVSS 4.0 0.0

CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N

Attack vector: Network
Attack complexity: Low
Attack requirements: Present
Privileges required: None
User interaction: Passive
Confidentiality (vulnerable system): Low
Integrity (vulnerable system): None
Availability (vulnerable system): None
Confidentiality (subsequent systems): None
Integrity (subsequent systems): None
Availability (subsequent systems): None

CVSS 3.1 3.1

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

Attack vector: Network
Attack complexity: High
Privileges required: None
User interaction: Required
Scope: Unchanged
Confidentiality: Low
Integrity: None
Availability: None

Weakness

CWE-178: Improper Handling of Case Sensitivity

The product does not properly account for differences in case sensitivity when accessing or determining the properties of a resource, leading to inconsistent results.

How to prevent it

Architecture and Design: Avoid making decisions based on names of resources (e.g. files) if those resources can have alternate names.
Implementation: Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does. When performing input validation, consider all potentially relevant properties, including length, type of input, the full range of acceptable values, missing or extra inputs, syntax, consistency across related fields, and conformance to business rules. As an example of business rule logic, "boat" may be syntactically valid because it only contains alphanumeric characters, but it is not valid if the input is only expected to contain colors such as "red" or "blue." Do not rely exclusively on looking for malicious or malformed inputs. This is likely to miss at least one undesirable input, especially if the code's environment changes. This can give attackers enough room to bypass the intended validation. However, denylists can be useful for detecting potential attacks or determining which inputs are so malformed that they should be rejected outright.
Implementation: Inputs should be decoded and canonicalized to the application's current internal representation before being validated (CWE-180). Make sure that the application does not decode the same input twice (CWE-174). Such errors could be used to bypass allowlist validation schemes by introducing dangerous inputs after they have been checked.

References

Advisories

Fixes and patches

Packages

github.com/django/django

Timeline

Jun 3, 2026 Published
Sep 10, 2026 Last updated by the source
Oct 31, 2026 Latest EPSS score

Advisory	Severity	Why it's related
GHSA-q238-5cxm-5c9h Django GeoDjango vulnerable to denial of service through deeply nested geometry collections	Medium	Also affects django
GHSA-wvqv-fj8w-qmhm Django GeoDjango spatial lookups allow file writes and outbound requests through GDAL raster parsing	High	Also affects django
GHSA-8qcx-xf44-272x Django: DomainNameValidator permits newline characters that may enable HTTP header injection	Medium	Also affects django
GHSA-crhf-3pfg-w68w Django: GDALRaster may over-read heap memory when constructed from bytes	Medium	Also affects django
GHSA-3h9f-r86x-qvjx Django: cache middleware may expose private responses when unrelated request cookies are present	Medium	Also affects django
GHSA-mm6v-q8q9-pgcf Django fails to prevent reuse of a partially-initialized connection after a failed `STARTTLS` handshake	Low	Also affects django
GHSA-h7pc-vwp9-298g Django: signed cookies are vulnerable to salt namespace collisions	Medium	Also affects django
GHSA-923m-gv2p-w5qp Django: has_vary_header may expose cached responses when Vary values contain whitespace	Medium	Also affects django

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