Inconsistent interpretation of HTTP requests in Jetty - CVE-2026-19203
Published: September 18, 2026
Vulnerability identifier: #VU150800
CSH Severity: Medium
CVSS v4: 8.3 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:H/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-19203
CWE-ID: CWE-444
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to perform HTTP request smuggling attacks.
The vulnerability exists due to inconsistent interpretation of HTTP requests in the HTTP chunk extension parser when processing a crafted chunked HTTP request containing a line feed in a chunk extension. A remote attacker can send a specially crafted chunked HTTP request to perform HTTP request smuggling attacks.
RFC7230 and RFC2616 compliance modes permit the line-feed condition.
Affected software
Jetty
How to mitigate CVE-2026-19203
Install security update from vendor's website.
Jetty - addressed in versions 9.4.64, 10.0.32, 11.0.32, 12.0.38, 12.1.12