Critical Security Update for Corosync: CVE-2026-81665 Vulnerability
Summary
RHSA-2026:69279: Red Hat Security Advisory: corosync security update. Affects corosync versions < 0:3.1.5-2.el8_6.2. Fixed in 0:3.1.5-2.el8_6.2. How to fix ↓
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Background
Corosync is an open-source project that provides a cluster engine for high availability and distributed systems. It facilitates communication between nodes in a cluster, ensuring data consistency and reliability. The package is widely used in various applications that require fault tolerance and resilience. However, it has recently been identified as vulnerable to a security flaw that could potentially compromise the integrity and availability of systems relying on it.
Vulnerability Detail
The vulnerability identified as CVE-2026-81665 affects the Corosync package, allowing unauthorized access and manipulation of cluster communications. This flaw originates from improper validation of input data, which could lead to denial of service or unauthorized data access. Attackers exploiting this vulnerability could disrupt cluster operations, leading to significant downtime and data loss. The vulnerability has a CVSS score of 7.5, indicating a high severity level.
How To Fix
Minimum fixed version
0:3.1.5-2.el8_6.2
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, users can restrict access to the Corosync service by implementing firewall rules to limit connections to trusted IP addresses only. This can be achieved using the following command:
sudo firewall-cmd --add-rich-rule="rule family='ipv4' source address='trusted_ip' accept"
Replace 'trusted_ip' with the actual IP address of the trusted node.
Conclusion
The Corosync package is critical for maintaining high availability in distributed systems. The CVE-2026-81665 vulnerability poses significant risks, and it is crucial for users to update to the patched version to safeguard their systems. Implementing temporary workarounds can provide additional protection until the update is applied.
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 cluster communications.
You can use the Vulert playground at Vulert Scanner to check if your application is affected by this vulnerability without needing to sign up.
The vulnerability has a CVSS score of 7.5, indicating a high severity level that could lead to significant security risks.
You can update the Corosync package by running the command 'sudo yum update corosync' in your terminal.
If you cannot apply the patch immediately, consider implementing firewall rules to restrict access to the Corosync service as a temporary workaround.
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