Critical OpenSSL Vulnerability Update: Heap Buffer Overflow and Denial of Service Risks
Summary
ALSA-2026:25237: Important: openssl security update. Affects openssl versions < 1:3.5.5-4.el10_2.alma.1. Fixed in 1:3.5.5-4.el10_2.alma.1. 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 computer networks. The recent vulnerabilities discovered in OpenSSL can lead to severe security risks, including data breaches and service disruptions.
Vulnerability Detail
The vulnerabilities in OpenSSL stem from multiple issues, including a heap buffer overflow due to signed integer overflow in Unicode output sizing (CVE-2026-7383) and a denial of service caused by heap out-of-bounds read during CMS password-based decryption (CVE-2026-9076). Other vulnerabilities include heap buffer over-read in ASN.1 decoding, acceptance of forged messages in CMS AuthEnvelopedData processing, and potential NULL pointer dereferences in various contexts. These vulnerabilities can lead to service interruptions, unauthorized access to sensitive information, and exploitation by malicious actors.
How To Fix
Minimum fixed version
1:3.5.5-4.el10_2.alma.1
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, users can limit access to the OpenSSL services or implement network-level security controls to mitigate the risk of exploitation until the packages are updated.
Conclusion
The recent OpenSSL vulnerabilities pose significant risks to systems relying on this toolkit for secure communications. It is crucial for users to update their packages to the latest patched versions to mitigate these risks effectively. Utilizing tools like Vulert can help in monitoring and managing vulnerabilities in open-source software.
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FAQ
The main vulnerabilities include heap buffer overflow, denial of service due to out-of-bounds reads, and various NULL pointer dereferences.
You can use the Vulert platform to monitor and alert for open-source vulnerabilities in your software by simply uploading your manifest file like package-lock.json.
The vulnerabilities can lead to service disruptions, unauthorized access to sensitive data, and potential exploitation by attackers.
Yes, you can limit access to OpenSSL services and implement network-level security measures as a temporary workaround.
For detailed information, refer to the CVE pages listed in the advisory or visit the Vulert website for real-time monitoring.
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