Critical Security Update for HAProxy: CVE-2026-55204
Summary
RHSA-2026:55859: Red Hat Security Advisory: haproxy security update. Affects haproxy versions < 0:1.8.27-5.el8_10.2. Fixed in 0:1.8.27-5.el8_10.2. How to fix ↓
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Background
HAProxy is a widely used open-source software that provides high availability, load balancing, and proxying for TCP and HTTP applications. It is known for its performance and reliability, making it a popular choice for managing web traffic. However, like any software, it is susceptible to vulnerabilities that can compromise its security and the systems it protects.
Vulnerability Detail
The vulnerability identified as CVE-2026-55204 affects HAProxy versions prior to 1.8.27-5.el8_10.2. This security flaw could allow an attacker to exploit the application, potentially leading to denial of service or unauthorized access to sensitive data. The vulnerability arises from improper handling of certain requests, which could be leveraged by malicious actors to disrupt service or gain unauthorized access.
How To Fix
Minimum fixed version
0:1.8.27-5.el8_10.2
This is the first release that contains the fix.
sudo dnf update haproxyTip — Not sure which version your app runs? Vulert can match this fix to it. Scan free →
Workaround
If immediate patching is not feasible, consider implementing network-level controls to restrict access to the HAProxy service, thereby mitigating potential exploitation until the update can be applied.
Conclusion
In summary, CVE-2026-55204 poses a significant security risk to HAProxy users. It is crucial to update to the latest patched version to mitigate potential threats. Regular monitoring and timely updates are essential for maintaining the security of your applications.
See every vulnerability recorded for haproxy →
FAQ
CVE-2026-55204 is a security vulnerability in HAProxy that could allow attackers to exploit the application, leading to denial of service or unauthorized access.
You can check your HAProxy version by running 'haproxy -v' in the terminal. If your version is below 1.8.27-5.el8_10.2, it is affected.
Failure to address this vulnerability could result in service disruptions or unauthorized access to sensitive data, compromising the security of your applications.
It is recommended to regularly check for updates and apply them promptly to ensure that your installation is secure and up-to-date.
Yes, Vulert can monitor your application for open-source vulnerabilities like CVE-2026-55204 using a manifest file such as package-lock.json, providing real-time alerts.
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