Critical Security Update for nginx:1.26 - Code Execution and Denial of Service Vulnerability
Summary
ALSA-2026:29151: Important: nginx:1.26 security update. Affects nginx versions < 2:1.26.3-9.module_el9.8.0+260+95b8e5ed.1. Fixed in 2:1.26.3-9.module_el9.8.0+260+95b8e5ed.1. How to fix ↓
Check if this vulnerability affects your application
Upload a manifest or SBOM and we'll show whether you're affected, plus every other risky package in the same scan.
No signup required · Results in about 60 seconds
Background
nginx is a widely used web and proxy server known for its high concurrency, performance, and low memory usage. It supports various protocols, including HTTP, and is often employed to serve static content and as a reverse proxy. The recent vulnerability affects multiple nginx packages in the AlmaLinux ecosystem, potentially compromising server integrity and availability.
Vulnerability Detail
The vulnerability identified as CVE-2026-9256 in nginx's ngx_http_rewrite_module allows for code execution and denial of service. This issue arises from improper handling of certain requests, which could lead to unauthorized code execution on the server or make the service unavailable to legitimate users. The ramifications of this vulnerability are severe, as it could allow attackers to gain control over the server or disrupt its operations.
How To Fix
Minimum fixed version
2:1.26.3-9.module_el9.8.0+260+95b8e5ed.1
This is the first release that contains the fix.
sudo dnf update nginxTip — Not sure which version your app runs? Vulert can match this fix to it. Scan free →
Workaround
As a temporary workaround, you may consider disabling the ngx_http_rewrite_module if it is not essential for your application. This can be done by commenting out the relevant configuration lines in your nginx configuration file.
Conclusion
The nginx vulnerability CVE-2026-9256 poses significant risks, including potential code execution and denial of service. It is crucial to update to the patched version to mitigate these risks. Users are encouraged to monitor their systems and apply necessary updates promptly.
See every vulnerability recorded for nginx →
FAQ
CVE-2026-9256 is a vulnerability in the nginx web server that allows for code execution and denial of service due to improper request handling.
You can check if your nginx installation is affected by using the Vulert playground at Vulert Scanner, which allows you to monitor vulnerabilities in your software without needing to sign up.
The risks include unauthorized code execution on the server and potential denial of service, which can disrupt service availability for legitimate users.
Yes, a patch is available in the form of an updated version of nginx. It is recommended to update to version 2:1.26.3-9.module_el9.8.0+260+95b8e5ed.1.
If you cannot update immediately, consider disabling the ngx_http_rewrite_module as a temporary workaround until you can apply the patch.
Related vulnerabilities
Recent vulnerabilities recorded for nginx.
