Critical Security Flaw in nginx: Heap Buffer Over-read and Memory Disclosure Vulnerabilities
Summary
RLSA-2026:59220: Important: nginx security update. Affects nginx versions < 2:1.26.3-6.el10_2.6. Fixed in 2:1.26.3-6.el10_2.6. 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 high-performance web and proxy server designed to handle a large number of concurrent connections efficiently. It is widely used for serving static content, load balancing, and as a reverse proxy. Despite its robust architecture, nginx is susceptible to certain vulnerabilities that can compromise its security and the integrity of the systems it serves.
Vulnerability Detail
The vulnerabilities identified in nginx include a heap buffer over-read (CVE-2026-56434) that allows for potential memory modification or denial of service, and a memory disclosure issue in the ngx_http_slice_module (CVE-2026-60005) that can lead to denial of service. These vulnerabilities can be exploited by attackers to manipulate server memory, potentially exposing sensitive information or causing service interruptions.
How To Fix
Minimum fixed version
2:1.26.3-6.el10_2.6
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
If immediate updating is not feasible, consider disabling the ngx_http_slice_module as a temporary workaround to mitigate the risk of exploitation until the patch can be applied.
Conclusion
The identified vulnerabilities in nginx pose significant risks that can lead to memory manipulation and denial of service. It is crucial to update to the patched version to safeguard your systems. Utilize tools like Vulert to stay informed about potential vulnerabilities in your software.
See every vulnerability recorded for nginx →
FAQ
The main vulnerabilities are a heap buffer over-read and memory disclosure in the ngx_http_slice_module, which can lead to memory manipulation and denial of service.
You can use tools like Vulert to monitor and alert for open-source vulnerabilities in your software. Visit Vulert Scanner to check if your application is affected.
The CVSS score for these vulnerabilities is 8.2, indicating a high severity level.
As a temporary measure, you can disable the ngx_http_slice_module to reduce the risk of exploitation until you can apply the patch.
The security update is provided by the Rocky Enterprise Software Foundation and Red Hat, who maintain and support the nginx package.
References
Related vulnerabilities
Recent vulnerabilities recorded for nginx.
