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Fencer Vulns
medium 4.9

CVE-2023-28837 json

Wagtail vulnerable to denial-of-service via memory exhaustion when uploading large files

published 2023-04-03 3 y ago modified 2026-09-10 1 mo ago also GHSA-33pv-vcgh-jfg9 , PYSEC-2023-56 , EUVD-2023-0279

cvss
4.9
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
1.1%
EPSS 1.1% chance of exploitation in 30 days, percentile 65%
public exploits
0
none known

Summary

Wagtail is an open source content management system built on Django. Prior to versions 4.1.4 and 4.2.2, a memory exhaustion bug exists in Wagtail's handling of uploaded images and documents. For both images and documents, files are loaded into memory during upload for additional processing. A user with access to upload images or documents through the Wagtail admin interface could upload a file so large that it results in a crash of denial of service.

The vulnerability is not exploitable by an ordinary site visitor without access to the Wagtail admin. It can only be exploited by admin users with permission to upload images or documents.

Image uploads are restricted to 10MB by default, however this validation only happens on the frontend and on the backend after the vulnerable code.

Patched versions have been released as Wagtail 4.1.4 and Wagtail 4.2.2). Site owners who are unable to upgrade to the new versions are encouraged to add extra protections outside of Wagtail to limit the size of uploaded files.

Patch / fix

  • pypi wagtail 4.1.4, 4.2.2
  • torchbox wagtail 4.1.4, 4.2.2

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
20 mo ago

Exploit prediction

1.07% chance of exploitation in the next 30 days, higher than 65% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 4.9 CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
NVD 3.1 4.9 CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
GitHub 3.1 4.4 CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H

Affected packages

ecosystem package affected fixed in
pypi wagtail
>=4.2, <4.2.2
<4.1.4
4.2.2
4.1.4

Affected products

  • wagtail wagtail

Classification

Weakness
  • CWE-400 Uncontrolled Resource Consumption
  • CWE-770 Allocation of Resources Without Limits or Throttling

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.