Critical Security Flaw in fence-agents Package: Authentication Bypass via Forged JSON Web Tokens
Summary
ALSA-2026:25902: Important: fence-agents security update. Affects fence-agents-aliyun versions < 4.16.0-21.el10_2.2. Fixed in 4.16.0-21.el10_2.2. How to fix ↓
Check if this vulnerability affects your application
Upload a manifest or SBOM and we'll show whether you're affected, plus every other risky package in the same scan.
No signup required · Results in about 60 seconds
Background
The fence-agents package is a collection of scripts designed for remote power management of cluster devices. It plays a crucial role in managing the availability of nodes within a cluster by allowing administrators to forcibly restart or remove failed or unreachable nodes. This functionality is essential for maintaining high availability and operational efficiency in clustered environments.
Vulnerability Detail
The vulnerability identified in the fence-agents package is an authentication bypass due to forged JSON Web Tokens (JWTs), specifically tracked under CVE-2026-48526. This flaw allows unauthorized users to gain access to functionalities that should be restricted, potentially leading to unauthorized control over cluster devices. The ramifications of this vulnerability could include unauthorized power management actions, which could disrupt services and compromise the integrity of the cluster.
How To Fix
Minimum fixed version
4.16.0-21.el10_2.2
This is the first release that contains the fix.
sudo dnf update fence-agents-aliyunTip — Not sure which version your app runs? Vulert can match this fix to it. Scan free →
Workaround
As a temporary measure, it is advisable to restrict access to the affected functionalities until the patch is applied. This can be done by modifying the access controls to limit who can execute power management commands.
Conclusion
The fence-agents package has a critical vulnerability that allows authentication bypass through forged JSON Web Tokens. It is essential to update to the patched version to mitigate risks associated with unauthorized access. Users should also consider using tools like Vulert for ongoing vulnerability monitoring.
See every vulnerability recorded for fence-agents-aliyun →
FAQ
CVE-2026-48526 is a vulnerability in the fence-agents package that allows authentication bypass through forged JSON Web Tokens.
You can use the Vulert playground at Vulert Scanner to check if your application is affected by this vulnerability without any signup.
The vulnerability could allow unauthorized users to control cluster devices, leading to service disruptions and compromised integrity.
You can update the package using the command: sudo dnf update fence-agents-aliyun fence-agents-all fence-agents-amt-ws ... (and so on for all affected packages).
Yes, Vulert provides real-time monitoring and alerts for open-source vulnerabilities using just a manifest file like package-lock.json.
Related vulnerabilities
Recent vulnerabilities recorded for fence-agents-aliyun.
