nginx vulnerabilities

Summary

It was discovered that nginx did not properly validate source addresses in the HTTP/3 QUIC module. A remote attacker could possibly use this issue to bypass authorization checks or rate limiting. This issue only affected Ubuntu 25.04 and Ubuntu 25.10. (CVE-2026-40460) It was discovered that nginx contained a use-after-free vulnerability in the ngx_http_ssl_module module when client certificate verification and OCSP validation were enabled. A remote attacker could use this issue to cause nginx to crash, resulting in a denial of service, or possibly modify data in memory. (CVE-2026-40701) It was discovered that nginx did not properly handle certain proxied responses in the ngx_http_charset_module module. A remote attacker could possibly use this issue to obtain sensitive information or cause nginx to crash, resulting in a denial of service. (CVE-2026-42934) It was discovered that nginx did not properly process certain SCGI and uWSGI responses. An attacker able to perform a machine-in-the-middle attack could possibly use this issue to obtain sensitive information or cause nginx to crash, resulting in a denial of service. (CVE-2026-42946) It was discovered that nginx incorrectly handled certain rewrite rules in the ngx_http_rewrite_module module. A remote attacker could use this issue to cause nginx to crash, resulting in a denial of service, or possibly execute arbitrary code. (CV Affected Ubuntu releases: 26.04, 25.10, 24.04, 22.04. CVEs: CVE-2026-9256, CVE-2026-40460, CVE-2026-40701, CVE-2026-42946, CVE-2026-42934.