Critical Arbitrary Code Execution Vulnerability in nginx Package
Summary
RLSA-2026:18063: Critical: nginx security update. Affects nginx versions < 2:1.26.3-2.el10_1.2. Fixed in 2:1.26.3-2.el10_1.2. How to fix ↓
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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, reverse proxy, and load balancing. The recent vulnerability identified as CVE-2026-42945 poses a significant risk to systems running vulnerable versions of nginx, potentially allowing attackers to execute arbitrary code.
Vulnerability Detail
The vulnerability, CVE-2026-42945, is classified as a critical security issue that allows for arbitrary code execution. This flaw arises from improper handling of certain requests, which could be exploited by an attacker to execute malicious code on the server. The ramifications of this vulnerability are severe, as it could lead to unauthorized access, data breaches, and full system compromise. The CVSS score for this vulnerability is 8.1, indicating a high level of risk.
How To Fix
Minimum fixed version
2:1.26.3-2.el10_1.2
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, users may consider restricting access to the nginx server or implementing additional security measures such as firewalls to mitigate potential exploitation until the package can be updated.
Conclusion
The nginx package has a critical vulnerability (CVE-2026-42945) that allows for arbitrary code execution. It is crucial for users to update to the patched version to mitigate risks. Implementing workarounds can provide temporary relief, but updating the software is the most effective solution.
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FAQ
CVE-2026-42945 is a critical vulnerability in the nginx package that allows for arbitrary code execution, posing significant security risks.
You can use the Vulert platform to monitor and alert for open-source vulnerabilities. Visit Vulert Scanner to check if your application is affected without needing to sign up.
If an immediate update is not possible, consider implementing security measures such as restricting access to the server or using firewalls to reduce exposure.
Failure to address this vulnerability could lead to unauthorized access, data breaches, and potential full system compromise.
For more details, refer to the CVE page associated with CVE-2026-42945, which provides comprehensive information about the vulnerability and its impact.
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