CVE-2023-28837 [Medium] | Denial of Service in Wagtail

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.

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2026-04-09	1.22%	1.30%	+0.08%
2	2026-04-05	0.26%	1.22%	+0.96%
3	2026-04-04	—	0.26%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2026-04-09

1.22%

1.30%

+0.08%

2026-04-05

0.26%

1.22%

+0.96%

2026-04-04

—

0.26%

—

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
4.9	3.1	MEDIUM	`CVSS:3.1/AV:N/AC:L/PR:H/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:H) They need powerful rights—admin, root, or similar—before this pays off. 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.	1.2	3.6	[email protected]
4.9	3.1	MEDIUM	`CVSS:3.1/AV:N/AC:L/PR:H/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:H) They need powerful rights—admin, root, or similar—before this pays off. 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.	1.2	3.6	[email protected]

Base score

Version

Severity

Vector

Exploitability

Impact

Score source

4.9

3.1

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:H/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:H): They need powerful rights—admin, root, or similar—before this pays off.
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.

1.2

3.6

[email protected]

4.9

3.1

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:H/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:H): They need powerful rights—admin, root, or similar—before this pays off.
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.

1.2

3.6

[email protected]

Affected software / configurations for CVE-2023-28837

Vendor	Product	Version	Raw CPE
torchbox	wagtail	< 4.1.4	cpe:2.3:a:torchbox:wagtail::::::::
torchbox	wagtail	>= 4.2, < 4.2.2	cpe:2.3:a:torchbox:wagtail::::::::

References for CVE-2023-28837

URL	Tags
https://docs.wagtail.org/en/stable/reference/settings.html#wagtailimages-max-upload-size	Product
https://github.com/wagtail/wagtail/commit/3c0c64642b9e5b8d28b111263c7f4bddad6c3880	Patch
https://github.com/wagtail/wagtail/commit/c9d2fcd650a88d76ae122646142245e5927a9165	Release Notes
https://github.com/wagtail/wagtail/commit/cfa11bbe00dbe7ce8cd4c0bbfe2a898a690df2bf	Patch
https://github.com/wagtail/wagtail/commit/d4022310cbe497993459c3136311467c7ac6329a	Release Notes
https://github.com/wagtail/wagtail/releases/tag/v4.1.4	Release Notes
https://github.com/wagtail/wagtail/releases/tag/v4.2.2	Release Notes
https://github.com/wagtail/wagtail/security/advisories/GHSA-33pv-vcgh-jfg9	Mitigation Vendor Advisory

URL

CVE-2023-28837 | Wagtail vulnerable to denial-of-service via memory exhaustion when uploading large files

Exploit prediction scoring system (EPSS) score for CVE-2023-28837

Common vulnerability scoring system (CVSS) metrics for CVE-2023-28837

Weakness enumeration for CVE-2023-28837

GitHub Security Advisory for CVE-2023-28837

Affected software / configurations for CVE-2023-28837

References for CVE-2023-28837