Ubuntu Security Notices USN-8495-1 USN-8495-1: nghttp2 vulnerability Publication date 2 July 2026 Overview nghttp2 could allow unintended access to network services. Releases 26.04 LTS 25.10 24.04 LTS 22.04 LTS Open side navigation Close side navigation Packages Details Update instructions References Packages nghttp2 - HTTP/2 C Library and tools Details It was discovered that the nghttp2 nghttpx proxy incorrectly handled HTTP/1.1 Upgrade requests that included a Content-Length header and body. A remote attacker could possibly use this issue to perform HTTP request and response smuggling attacks against backend services. It was discovered that the nghttp2 nghttpx proxy incorrectly handled HTTP/1.1 Upgrade requests that included a Content-Length header and body. A remote attacker could possibly use this issue to perform HTTP request and response smuggling attacks against backend services. Update instructions In general, a standard system update will make all the necessary changes. Learn more about how to get the fixes. The problem can be corrected by updating your system to the following package versions: Ubuntu Release Package Version 26.04 LTS resolute nghttp2 – 1.68.0-2ubuntu0.2 25.10 questing nghttp2 – 1.64.0-1.1ubuntu1.2 24.04 LTS noble nghttp2 – 1.59.0-1ubuntu0.4 22.04 LTS jammy nghttp2 – 1.43.0-1ubuntu0.4 Reduce your security exposure Ubuntu Pro provides ten-year security coverage to 25,000+ packages in Main and Universe repositories, and it is free for up to five machines. Get Ubuntu Pro References CVE-2026-58055 CVE-2026-58055