A vulnerability (CVE-2026-42945, CVSS 8.1 HIGH) in nginx's `ngx_http_rewrite_module` allows a remote attacker to cause a denial of service or potentially execute arbitrary code by sending specially crafted network traffic that exploits improper handling of certain rewrite directives. The vulnerability affects multiple Ubuntu LTS releases, and the standard system update mechanism provides the necessary patches, with specific fixed package versions listed for each release (e.g., nginx 1.28.3-2ubuntu1.1 for Ubuntu 26.04 LTS).
Ubuntu Security Notices USN-8271-1 USN-8271-1: nginx vulnerability Publication date 14 May 2026 Overview nginx could be made to crash or run programs if it received specially crafted network traffic. Releases 26.04 LTS 25.10 24.04 LTS 22.04 LTS Open side navigation Close side navigation Packages Details Update instructions References Packages nginx - small, powerful, scalable web/proxy server Details It was discovered that the nginx ngx_http_rewrite_module component incorrectly handled certain rewrite directives. A remote attacker could use this issue to cause nginx to crash, resulting in a denial of service, or possibly execute arbitrary code. It was discovered that the nginx ngx_http_rewrite_module component incorrectly handled certain rewrite directives. A remote attacker could use this issue to cause nginx to crash, resulting in a denial of service, or possibly execute arbitrary code. 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 nginx – 1.28.3-2ubuntu1.1 nginx-core – 1.28.3-2ubuntu1.1 nginx-extras – 1.28.3-2ubuntu1.1 nginx-full – 1.28.3-2ubuntu1.1 nginx-light – 1.28.3-2ubuntu1.1 25.10 questing nginx – 1.28.0-6ubuntu1.3 nginx-core – 1.28.0-6ubuntu1.3 nginx-extras – 1.28.0-6ubuntu1.3 nginx-full – 1.28.0-6ubuntu1.3 nginx-light – 1.28.0-6ubuntu1.3 24.04 LTS noble nginx – 1.24.0-2ubuntu7.8 nginx-core – 1.24.0-2ubuntu7.8 nginx-extras – 1.24.0-2ubuntu7.8 nginx-full – 1.24.0-2ubuntu7.8 nginx-light – 1.24.0-2ubuntu7.8 22.04 LTS jammy nginx – 1.18.0-6ubuntu14.11 nginx-core – 1.18.0-6ubuntu14.11 nginx-extras – 1.18.0-6ubuntu14.11 nginx-full – 1.18.0-6ubuntu14.11 nginx-light – 1.18.0-6ubuntu14.11 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-2026-42945 CVE-2026-42945