Critical Security Update for ruby4.0: Addressing Denial of Service and Command Injection Vulnerabilities
Summary
ALSA-2026:33540: Important: ruby4.0 security update. Affects ruby4.0 versions < 4.0.3-35.el10_2. Fixed in 4.0.3-35.el10_2. How to fix ↓
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Background
Ruby is an interpreted scripting language known for its simplicity and flexibility, widely used for web development and system management tasks. The ruby4.0 package provides essential tools and libraries for Ruby programming, including the net-imap library, which facilitates communication with IMAP servers. However, recent vulnerabilities have been identified that could compromise the security of applications relying on this package.
Vulnerability Detail
The vulnerabilities in ruby4.0 stem from issues within the net-imap library. Specifically, CVE-2026-42245 allows for Denial of Service attacks via crafted IMAP responses, potentially causing applications to crash or become unresponsive. CVE-2026-42258 presents an IMAP Command Injection risk through the use of Symbol Arguments, which could allow attackers to execute arbitrary commands. Additionally, CVE-2026-42246 exposes applications to information disclosure via man-in-the-middle attacks that bypass TLS encryption, compromising sensitive data.
How To Fix
Minimum fixed version
4.0.3-35.el10_2
This is the first release that contains the fix.
sudo dnf update ruby4.0Tip — Not sure which version your app runs? Vulert can match this fix to it. Scan free →
Workaround
As a temporary measure, users can mitigate the risk of these vulnerabilities by avoiding the use of the net-imap library until the package is updated. Additionally, implementing strict input validation and monitoring network traffic for unusual patterns may help reduce the risk of exploitation.
Conclusion
The ruby4.0 package has critical vulnerabilities that require immediate attention. By updating to the latest patched versions, users can protect their applications from potential attacks. Utilizing tools like Vulert can further enhance security by providing real-time monitoring for open-source vulnerabilities.
See every vulnerability recorded for ruby4.0 →
FAQ
The vulnerabilities can lead to Denial of Service attacks, command injection, and information disclosure, potentially compromising application integrity and user data.
You can use Vulert, which monitors open-source vulnerabilities in your software. Simply upload your manifest file like package-lock.json to check for vulnerabilities.
Consider implementing workarounds such as avoiding the use of the net-imap library and enhancing input validation to mitigate risks until an update can be applied.
While specific exploits may not be publicly available, the nature of the vulnerabilities suggests that they could be exploited by attackers to disrupt services or gain unauthorized access.
Detailed information can be found on the CVE pages for CVE-2026-42245, CVE-2026-42246, and CVE-2026-42258, which provide insights into the vulnerabilities and their impacts.
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