CRLF injection in Netty - CVE-2025-67735
Published: December 15, 2025 / Updated: February 3, 2026
Vulnerability identifier: #VU119966
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2025-67735
CWE-ID: CWE-93
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Netty project
Affected software:
Netty
Netty
Detailed vulnerability description
The vulnerability allows a remote attacker to inject arbitrary data in server response.
The vulnerability exists due to insufficient validation of attacker-supplied data in io.netty.handler.codec.http.HttpRequestEncoder. A remote attacker can pass specially crafted data to the application containing CR-LF characters and modify application behavior.
How to mitigate CVE-2025-67735
Install updates from vendor's website.