Django 4.2~4.2.30,5.2~5.2.13,6.0~6.0.4 MP Degrade via Base64 Whitespace
CVE-2026-33033 Published on April 7, 2026
Potential denial-of-service vulnerability in MultiPartParser via base64-encoded file upload
An issue was discovered in 6.0 before 6.0.4, 5.2 before 5.2.13, and 4.2 before 4.2.30.
`MultiPartParser` allows remote attackers to degrade performance by submitting multipart uploads with `Content-Transfer-Encoding: base64` including excessive whitespace.
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.
Vulnerability Analysis
CVE-2026-33033 can be exploited with network access, and requires small amount of user privileges. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity, and a high impact on availability.
Timeline
Initial report received.
Vulnerability confirmed. 26 days later.
Security release issued. 21 days later.
Weakness Type
Inefficient Algorithmic Complexity
An algorithm in a product has an inefficient worst-case computational complexity that may be detrimental to system performance and can be triggered by an attacker, typically using crafted manipulations that ensure that the worst case is being reached.
Products Associated with CVE-2026-33033
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Affected Versions
djangoproject Django:- Version 6.0 and below 6.0.4 is affected.
- Version 6.0.4 is unaffected.
- Version 5.2 and below 5.2.13 is affected.
- Version 5.2.13 is unaffected.
- Version 4.2 and below 4.2.30 is affected.
- Version 4.2.30 is unaffected.