How severe is CVE-2023-28837?

CVE-2023-28837 has a CVSS score of 4.9/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2023-28837?

CVE-2023-28837 affects the following packages: wagtail (PyPI), wagtail (PyPI). Ecosystems affected: PyPI.

How do I fix CVE-2023-28837?

Update wagtail to 4.2.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-28837 is resolved across your whole dependency graph.

How do I detect CVE-2023-28837 in my PyPI dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for wagtail, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2023-28837 if there is no patch (or I can't update yet)?

Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.

Is CVE-2023-28837 actively exploited in the wild?

No public exploit code has been indexed for CVE-2023-28837 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2023-28837?

CVE-2023-28837 has an EPSS (Exploit Prediction Scoring System) score of 1.1%, placing it in the 65th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2023-28837?

CVE-2023-28837 is classified as Uncontrolled Resource Consumption (CWE-400), CWE-770 (CWE-770). These weakness types describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2023-28837 published, and has it been updated?

CVE-2023-28837 was published on April 3, 2023 and was last updated on October 28, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐍

🐍 PyPI

Not in CISA KEV

MEDIUM severity

CVE-2023-28837 — wagtail

MEDIUMFix: wagtail/wagtail@3c0c646

CVE-2023-28837 is a medium-severity (CVSS 4.9) Uncontrolled Resource Consumption vulnerability in wagtail. A fix is available for wagtail — see the affected versions and patch details below.

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

Also known asGHSA-33pv-vcgh-jfg9PYSEC-2023-56

Published

Apr 3, 2023

Updated

Oct 28, 2026

Affected

2 pkgs

Patched

2 / 2

Exploits

None indexed

Exploitation data as of Oct 29, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2023-28837.

EPSS Exploitation Probability

via FIRST.org ↗

1.1%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs65th percentile — riskier than 65% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

2 pkgs affected

🐍wagtail🐍wagtail

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.

Description

Impact

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 or 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.

Patches

Patched versions have been released as Wagtail 4.1.4 (for the LTS 4.1 branch) and Wagtail 4.2.2 (for the current 4.2 branch).

Workarounds

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. Exactly how this is done will vary based on your hosting environment, but here are a few references for common setups:

Nginx: client_max_body_size
Apache: LimitRequestBody
Cloudflare: Already imposes a limit of 100MB - 500MB depending on plan
CloudFront: SizeConstraint
Traefik: traefik.http.middlewares.limit.buffering.maxRequestBodyBytes

The changes themselves are deep inside Wagtail, making patching incredibly difficult.

Affected Packages

2 total 2 fixed

Ecosystem	Package	Vulnerable range	Fix
🐍PyPI	`wagtail`	≥ 4.2&&< 4.2.2	4.2.2`pip install --upgrade 'wagtail==4.2.2'`
🐍PyPI	`wagtail`	all versions	4.1.4`pip install --upgrade 'wagtail==4.1.4'`

Affected Products

1 product · 2 configurations

Application

wagtailtorchbox

≥ 4.2 && < 4.2.2

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for wagtail, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update wagtail to 4.2.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-28837 is resolved across your whole dependency graph.
Workarounds
Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.

Frequently Asked Questions

### Impact 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 or 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 defau