CVE Vulnerabilities

CVE-2026-8404

Improper Handling of Case Sensitivity

Published: Jun 03, 2026 | Modified: Jun 17, 2026
CVSS 3.x
5.3
MEDIUM
Source:
NVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
CVSS 2.x
RedHat/V2
RedHat/V3
3.1 LOW
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:N/A:N
Ubuntu
LOW
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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.

Weakness

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

Affected Software

NameVendorStart VersionEnd Version
DjangoDjangoproject5.2 (including)5.2.15 (excluding)
DjangoDjangoproject6.0 (including)6.0.6 (excluding)
Python-djangoUbuntuquesting*

Extended Description

Improperly handled case sensitive data can lead to several possible consequences, including:

Potential Mitigations

  • 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.

References