Ubuntu 26.04 LTS Nginx Important Denial of Service Regression USN-8398-2

ubuntu

June 9, 2026

USN-8398-1 introduced a regression in nginx

Summary

USN-8398-1 introduced a regression in nginx

Software Description:

- nginx: small, powerful, scalable web/proxy server

Details:

USN-8398-1 fixed a vulnerability in nginx. The update introduced a

regression causing nginx to crash when being used with external modules.

This update reverts the fix for CVE-2026-49975 pending further

investigation.

We apologize for the inconvenience.

Original advisory details:

It was discovered that nginx incorrectly handled certain cookie headers in

the HTTP/2 implementation. A remote attacker could possibly use this issue

to cause nginx to consume excessive resources, resulting in a denial of

service.

Topics Covered

security advisory denial of service Ubuntu important nginx regression

Update Instructions

The problem can be corrected by updating your system to the following
package versions:

Ubuntu 26.04 LTS
  nginx                           1.28.3-2ubuntu1.4
  nginx-core                      1.28.3-2ubuntu1.4
  nginx-extras                    1.28.3-2ubuntu1.4
  nginx-full                      1.28.3-2ubuntu1.4
  nginx-light                     1.28.3-2ubuntu1.4

Ubuntu 25.10
  nginx                           1.28.0-6ubuntu1.6
  nginx-core                      1.28.0-6ubuntu1.6
  nginx-extras                    1.28.0-6ubuntu1.6
  nginx-full                      1.28.0-6ubuntu1.6
  nginx-light                     1.28.0-6ubuntu1.6

Ubuntu 24.04 LTS
  nginx                           1.24.0-2ubuntu7.11
  nginx-core                      1.24.0-2ubuntu7.11
  nginx-extras                    1.24.0-2ubuntu7.11
  nginx-full                      1.24.0-2ubuntu7.11
  nginx-light                     1.24.0-2ubuntu7.11

Ubuntu 22.04 LTS
  nginx                           1.18.0-6ubuntu14.14
  nginx-core                      1.18.0-6ubuntu14.14
  nginx-extras                    1.18.0-6ubuntu14.14
  nginx-full                      1.18.0-6ubuntu14.14
  nginx-light                     1.18.0-6ubuntu14.14

In general, a standard system update will make all the necessary changes.