Critical Stack-Based Buffer Overflow in Apache HTTP Server (apache2) - CVE-2026-63292
Summary
ALPINE-CVE-2026-63292: Stack-based buffer overflow in mod_vhost_alias in Apache Software Foundation Apache HTTP Server through 2.4.68 on all platforms allows a remote client to cause a denial of service or potentially execute arbitrary code vi... Affects apache2 versions < 2.4.69-r0. Fixed in 2.4.69-r0. How to fix ↓
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Background
Apache HTTP Server, commonly referred to as Apache, is a widely used open-source web server software that enables the hosting of websites and applications. It is known for its flexibility, power, and extensive feature set, including support for various protocols and modules. However, the software is vulnerable to a stack-based buffer overflow, specifically in the mod_vhost_alias module, which can lead to severe security risks if not addressed promptly.
Vulnerability Detail
The vulnerability identified as CVE-2026-63292 is a stack-based buffer overflow in the mod_vhost_alias module of Apache HTTP Server versions up to 2.4.68. This flaw allows a remote client to send an HTTP request with a Host header exceeding 8192 bytes, particularly when the VirtualDocumentRoot uses a hostname format specifier and the LimitRequestFieldSize is configured above the default value. The consequences of this vulnerability include potential denial of service and the possibility of executing arbitrary code, posing a significant threat to server integrity and security.
How To Fix
Minimum fixed version
2.4.69-r0
This is the first release that contains the fix.
sudo apk add --upgrade apache2Tip — Not sure which version your app runs? Vulert can match this fix to it. Scan free →
Workaround
As a temporary workaround, users can lower the LimitRequestFieldSize to a value below the default or avoid using the VirtualDocumentRoot with hostname format specifiers until the upgrade is completed.
Conclusion
CVE-2026-63292 represents a critical vulnerability in the Apache HTTP Server that can lead to severe security implications. Users are strongly advised to upgrade to the patched version 2.4.69 to protect their systems from potential exploits. For those unable to upgrade immediately, temporary workarounds should be employed to mitigate risks.
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FAQ
CVE-2026-63292 is a vulnerability in the Apache HTTP Server that allows for a stack-based buffer overflow, potentially leading to denial of service or arbitrary code execution.
You can check if your Apache server is affected by using the Vulert playground at Vulert Scanner, which analyzes your manifest file for vulnerabilities.
The risks include potential denial of service, which can disrupt service availability, and the possibility of executing arbitrary code, which can compromise server security.
Yes, a patch is available in Apache HTTP Server version 2.4.69 and later. It is recommended to upgrade to this version to mitigate the vulnerability.
If an immediate upgrade is not possible, consider implementing workarounds such as lowering the LimitRequestFieldSize or avoiding the use of VirtualDocumentRoot with hostname format specifiers.
References
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