DSA-6575-1 release notes and known issues

Summary

Several vulnerabilities were discovered in nginx, a high performance web and reverse proxy server. Depending on the configuration, these could result in memory corruption, denial of service, injection of requests to backend servers, or bypass of client certificate authentication. CVE-2026-15176 Mapping a rewritten request URI to a filesystem path in a location using the alias directive could cause a buffer overflow. CVE-2026-93479 Evaluation of string expressions in the HTTP and stream modules could overwrite reserved buffer space, resulting in a buffer overflow. Affected operations include evaluation of variable document roots and access log paths. The affected code was introduced into the trixie package by an earlier security backport. CVE-2026-95101 Incorrect handling of fragmented unknown HTTP/3 frames could cause their contents to be treated as request body data. When proxying requests, this could allow injection of requests into a backend server or bypass of request body size limits. CVE-2026-97205 A counter tracking pending asynchronous operations could overflow, causing request memory to be freed while still in use. This use-after-free could result in memory corruption or denial of service. CVE-2026-97629 Incomplete synchronisation of TLS session ticket keys between worker processes could leave a worker using uninitialised key material. This could allow forged TLS sessions and bypass of client certificate authentication. https://security-tracker.debian.org/tracker/DSA-6575-1

Improvements and security content

• Several vulnerabilities were discovered in nginx, a high performance web and reverse proxy server. Depending on the configuration, these could result in memory corruption, denial of service, injection of requests to backend servers, or bypass of client certificate authentication. CVE-2026-15176 Mapping a rewritten request URI to a filesystem path in a location using the alias directive could cause a buffer overflow. CVE-2026-93479 Evaluation of string expressions in the HTTP and stream modules could overwrite reserved buffer space, resulting in a buffer overflow. Affected operations include evaluation of variable document roots and access log paths. The affected code was introduced into the trixie package by an earlier security backport. CVE-2026-95101 Incorrect handling of fragmented unknown HTTP/3 frames could cause their contents to be treated as request body data. When proxying requests, this could allow injection of requests into a backend server or bypass of request body size limits. CVE-2026-97205 A counter tracking pending asynchronous operations could overflow, causing request memory to be freed while still in use. This use-after-free could result in memory corruption or denial of service. CVE-2026-97629 Incomplete synchronisation of TLS session ticket keys between worker processes could leave a worker using uninitialised key material. This could allow forged TLS sessions and bypass of client certificate authentication. https://security-tracker.debian.org/tracker/DSA-6575-1

Affected products and versions

Recommended action

Review the official publisher document before deployment.

Lifecycle connections

These links connect the publisher update to related Lifecycle records without treating the update publication date as an end-of-support date.

Official publisher evidence