CVE-2026-33033 | 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.

Published: 2026-04-07 Last update: 2026-04-13 Assigner: 6a34fbeb-21d4-45e7-8e0a-62b95bc12c92 Source: 6a34fbeb-21d4-45e7-8e0a-62b95bc12c92
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-33033 is rated Low Risk (30.5/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.04%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-33033

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-04-21 0.10% 0.04% -0.06%
2 2026-04-08 — 0.10% —

Full EPSS history (2 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-33033

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.5 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 2.8 3.6 134c704f-9b21-4f2e-91b3-4a467353bcc0

Weakness enumeration for CVE-2026-33033

GitHub Security Advisory for CVE-2026-33033

GHSA-5mf9-h53q-7mhq · Severity: medium · Ecosystem: pip — Django has potential DoS via MultiPartParser through crafted multipart uploads

OS Trackers for CVE-2026-33033

vendor priority summary link
alpine — CVE-2026-33033: 1 source package rows (py3-django); 2 state rows across 2 repos (3.23-community, edge-community); fixed 2, open 0. https://security.alpinelinux.org/vuln/CVE-2026-33033
debian not yet assigned CVE-2026-33033 not yet assigned priority: Debian including 1 source packages (python-django), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): open 3, resolved 2. https://security-tracker.debian.org/tracker/CVE-2026-33033
redhat medium — https://access.redhat.com/security/cve/CVE-2026-33033
suse medium CVE-2026-33033 severity moderate: SUSE including 5 source package names (python311-Django4-4.2.30-1.1, python313-Django4-4.2.30-1.1, python313-Django6-6.0.4-1.1, python314-Django4-4.2.30-1.1, python314-Django6-6.0.4-1.1), 5 product×package rows across 1 product lines (openSUSE Tumbleweed): Fixed 5. https://www.suse.com/security/cve/CVE-2026-33033/
ubuntu medium CVE-2026-33033 medium priority: Ubuntu including 1 source packages (python-django), 8 status rows across 8 suites (bionic, focal, jammy, noble, questing, trusty, upstream, xenial): released 8. https://ubuntu.com/security/CVE-2026-33033

Affected software / configurations for CVE-2026-33033

Vendor Product Version Raw CPE
djangoproject django >= 4.2, < 4.2.30 cpe:2.3:a:djangoproject:django:*:*:*:*:*:*:*:*
djangoproject django >= 5.2, < 5.2.13 cpe:2.3:a:djangoproject:django:*:*:*:*:*:*:*:*
djangoproject django >= 6.0, < 6.0.4 cpe:2.3:a:djangoproject:django:*:*:*:*:*:*:*:*

References for CVE-2026-33033

cvelogic Threat Intelligence