# CVE-2026-19203: jetty12: A client may issue specially crafted HTTP/1.1 chunked requests to a Jetty server that cause Jetty and an intermediary...

CVE-2026-19203 is fixed in jetty12 on 1 platform by DEBIAN-CVE-2026-19203 (version 12.0.39-1), released September 8, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-19203
- Priority: Routine
- CVSS: n/a
- EPSS: 0.0031
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Sep 8, 2026

## Description

A client may issue specially crafted HTTP/1.1 chunked requests to a Jetty server that cause Jetty and an intermediary proxy to interpret different request boundaries, potentially resulting in HTTP request smuggling.     This is caused by Jetty accepting a lone LF character as a terminator in parts of chunked request parsing. Depending on the Jetty version and configured HTTP compliance mode, this may occur in chunk extensions, chunk data termination, or trailer termination.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | jetty12 Debian 14 | 12.0.39-1 | [DEBIAN-CVE-2026-19203](https://patchblox.com/security/data/fix/linux/debian-cve-2026-19203.md) | Sep 8, 2026 |

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Data as of 2026-11-09T01:18:40Z 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 Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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