Critical Security Vulnerability in Corosync: CVE-2026-81665
Summary
RHSA-2026:69280: Red Hat Security Advisory: corosync security update. Affects corosync versions < 0:3.1.0-3.el8_4.3. Fixed in 0:3.1.0-3.el8_4.3. How to fix ↓
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Background
Corosync is an open-source cluster engine that provides a reliable messaging layer for high-availability applications. It is widely used in various systems to ensure that services remain available even in the event of failures. The package is integral to maintaining communication between nodes in a cluster, making its security paramount. This vulnerability affects multiple versions of Corosync, particularly in the Red Hat ecosystem, potentially exposing systems to significant risks.
Vulnerability Detail
The vulnerability identified as CVE-2026-81665 allows for unauthorized access and manipulation of the Corosync messaging layer. This could lead to denial of service or unauthorized data access, severely impacting the integrity and availability of clustered applications. The flaw originates from improper validation of messages, which could be exploited by an attacker to disrupt communication between nodes or gain unauthorized access to sensitive information.
How To Fix
Minimum fixed version
0:3.1.0-3.el8_4.3
This is the first release that contains the fix.
sudo dnf update corosyncTip — Not sure which version your app runs? Vulert can match this fix to it. Scan free →
Workaround
As a temporary workaround, consider isolating the affected systems from external networks to mitigate the risk of exploitation until the patch can be applied. Additionally, monitoring network traffic for unusual patterns may help identify potential exploitation attempts.
Conclusion
The CVE-2026-81665 vulnerability in Corosync poses a significant risk to systems relying on this package for high-availability applications. It is crucial to apply the available patch promptly and consider temporary workarounds to mitigate risks until the update can be implemented.
See every vulnerability recorded for corosync →
FAQ
CVE-2026-81665 is a security vulnerability in the Corosync package that allows unauthorized access and manipulation of the messaging layer.
You can use the Vulert playground at Vulert Scanner to check if your application is affected by this vulnerability without any signup.
The vulnerability can lead to denial of service or unauthorized data access, compromising the integrity and availability of clustered applications.
Yes, a patch is available in version 0:3.1.0-3.el8_4.3 of the Corosync package.
If you cannot apply the patch immediately, consider isolating the affected systems from external networks and monitoring for unusual network traffic.
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