# CVE-2023-3223: undertow: A flaw was found in undertow

CVE-2023-3223 is fixed in undertow on 1 platform by DEBIAN-CVE-2023-3223 (version 2.3.18-1), released September 27, 2023. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2023-3223
- Priority: High
- CVSS: 7.5 (high)
- EPSS: 0.0266
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Sep 27, 2023

## Description

A flaw was found in undertow. Servlets annotated with @MultipartConfig may cause an OutOfMemoryError due to large multipart content. This may allow unauthorized users to cause remote Denial of Service (DoS) attack. If the server uses fileSizeThreshold to limit the file size, it's possible to bypass the limit by setting the file name in the request to null.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | undertow Debian 14 | 2.3.18-1 | [DEBIAN-CVE-2023-3223](https://patchblox.com/security/data/fix/linux/debian-cve-2023-3223.md) | Sep 27, 2023 |

---

Data as of 2026-11-08T06:59:42Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

Free to use with attribution: show "Data: Patchblox Patch Radar" with a link to https://patchblox.com/security/patch-radar. Terms, including what needs a written agreement: https://patchblox.com/security/patch-radar/use-the-data

Product names, logos and trademarks shown on Patch Radar belong to their respective owners. They are used only to identify the software each security fix applies to and to help readers find their platform. Their use does not imply any affiliation with, or endorsement by, those owners, and Patchblox is not affiliated with any of them.