Netty vulnerabilities

Summary

It was discovered that Netty's HTTP proxy handler did not properly validate headers when constructing CONNECT requests. An attacker could possibly use this issue to inject arbitrary HTTP headers into CONNECT requests. This issue only affected Ubuntu 18.04 LTS, Ubuntu 20.04 LTS, Ubuntu 22.04 LTS, Ubuntu 24.04 LTS, and Ubuntu 26.04 LTS. (CVE-2026-42578) It was discovered that Netty's DNS codec did not properly enforce domain name constraints. An attacker could possibly use this issue to bypass domain name validation, or cause Netty to consume resources, leading to a denial of service. This issue only affected Ubuntu 20.04 LTS, Ubuntu 22.04 LTS, Ubuntu 24.04 LTS, and Ubuntu 26.04 LTS. (CVE-2026-42579) It was discovered that Netty did not correctly handle HTTP/1.0 requests containing both a Transfer-Encoding and Content-Length header. A remote attacker could possibly use this issue to perform HTTP request smuggling attacks. (CVE-2026-42581) Violeta Georgieva discovered that Netty incorrectly paired responses with requests when handling informational HTTP responses. A remote attacker could possibly use this issue to perform HTTP request smuggling attacks. (CVE-2026-42584) Violeta Georgieva discovered that Netty incorrectly parsed malformed Transfer-Encoding headers. A remote attacker could possibly use this issue to perform HTTP request smuggling attacks. (CVE-2026-42585) It was dis Affected Ubuntu releases: 26.04, 24.04, 22.04, 20.04, 18.04, 16.04, 14.04. CVEs: CVE-2026-42586, CVE-2026-42579, CVE-2026-42585, CVE-2026-42581, CVE-2026-42584, CVE-2026-42578.