SB2026082124 - Ubuntu update for netty



SB2026082124 - Ubuntu update for netty

Published: August 21, 2026

Security Bulletin ID SB2026082124
CSH Severity
Medium
Patch available
YES
Number of vulnerabilities 2
Exploitation vector Remote access
Highest impact Denial of service

Breakdown by Severity

Medium 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 2 vulnerabilities.


1) Resource exhaustion (CVE-ID: CVE-2025-55163)

CWE-ID: CWE-400 - Resource exhaustion

CVSSv4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]


The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to application does not properly control consumption of internal resources when handling HTTP/2 requests. A remote attacker can trigger resource exhaustion and perform a denial of service (DoS) attack.


2) CRLF injection (CVE-ID: CVE-2025-67735)

CWE-ID: CWE-93 - Improper Neutralization of CRLF Sequences ('CRLF Injection')

CVSSv4: 6.9 [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]


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.


Remediation

Install update from vendor's website.