Critical OpenSSL Vulnerability: Heap Buffer Overflow and Denial of Service Risks
Summary
RLSA-2026:25239: Important: openssl security update. Affects openssl versions < 1:3.5.5-4.el9_8. Fixed in 1:3.5.5-4.el9_8. How to fix ↓
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Background
OpenSSL is a widely used toolkit that implements the Secure Sockets Layer (SSL) and Transport Layer Security (TLS) protocols, along with a comprehensive general-purpose cryptography library. It is essential for secure communications over networks. However, vulnerabilities in OpenSSL can expose systems to significant security risks, including data breaches and service disruptions.
Vulnerability Detail
The OpenSSL vulnerabilities stem from multiple issues, including a heap buffer overflow due to signed integer overflow in Unicode output sizing, which can lead to memory corruption. Additionally, a denial of service can occur due to heap out-of-bounds reads in CMS password-based decryption. Other vulnerabilities include potential NULL pointer dereferences, unbounded memory growth, and incorrect tag processing in cryptographic operations. These vulnerabilities can lead to severe consequences, such as unauthorized access to sensitive data and service outages.
How To Fix
Minimum fixed version
1:3.5.5-4.el9_8
This is the first release that contains the fix.
sudo dnf update opensslTip — Not sure which version your app runs? Vulert can match this fix to it. Scan free →
Workaround
As a temporary measure, you can limit the exposure of your OpenSSL implementation by restricting access to vulnerable components and monitoring for unusual activity. However, the best practice is to apply the patch as soon as possible.
Conclusion
In summary, the OpenSSL vulnerabilities present critical risks that can lead to severe security breaches and service disruptions. It is essential to update to the latest patched version to mitigate these risks effectively. Utilizing tools like Vulert can help monitor and manage vulnerabilities in your software.
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FAQ
The CVSS score for this vulnerability is 9.1, indicating a critical level of severity.
The vulnerabilities can lead to memory corruption, denial of service, unauthorized data access, and service disruptions.
You can use the Vulert playground at Vulert Scanner to check if your application is affected by this vulnerability without requiring any signup.
Yes, Vulert can monitor and alert in real-time for open-source vulnerabilities in your software using just a manifest file like package-lock.json.
If immediate updates are not possible, implement strict access controls and monitor your systems for any suspicious activity as a temporary workaround.
References
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