Critical Vulnerability in Sudo Package: TZ Environment Variable Bypass
Summary
RLSA-2026:75571: Important: sudo security update. Affects sudo versions < 0:1.9.17p2-3.el9_8.3. Fixed in 0:1.9.17p2-3.el9_8.3. How to fix ↓
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Background
The Sudo package is a widely used utility that allows system administrators to grant specific users the ability to execute privileged commands without needing to log in as the root user. This functionality is crucial for system management and security, as it helps maintain control over user permissions while allowing necessary access for administrative tasks. However, vulnerabilities in Sudo can pose significant risks to system security, particularly when they allow unauthorized access or privilege escalation.
Vulnerability Detail
The vulnerability identified as CVE-2026-96512 allows an attacker to bypass time-based authorization checks by manipulating the TZ environment variable. This could enable unauthorized users to execute commands that should be restricted based on time constraints, potentially leading to unauthorized access to sensitive system functions. The implications of this vulnerability are severe, as it undermines the integrity of the Sudo command's authorization mechanisms, allowing for potential privilege escalation and unauthorized command execution.
How To Fix
Minimum fixed version
0:1.9.17p2-3.el9_8.3
This is the first release that contains the fix.
sudo dnf update sudoTip — Not sure which version your app runs? Vulert can match this fix to it. Scan free →
Workaround
As a temporary workaround, system administrators may consider restricting the use of the TZ environment variable for users who have access to Sudo until the package can be updated. This can be done by modifying user profiles or session settings to unset or limit the TZ variable.
Conclusion
The vulnerability in the Sudo package, identified as CVE-2026-96512, poses a significant risk due to its ability to bypass time-based authorization checks. It is crucial for system administrators to update to the patched version to secure their systems against potential unauthorized access. Utilizing tools like Vulert can help in monitoring and managing such vulnerabilities effectively.
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FAQ
The CVSS score of this vulnerability is 7.8, indicating a high level of severity.
You can use Vulert to monitor and alert for open-source vulnerabilities in your software. By simply uploading your manifest file like package-lock.json, you can check if your application is affected.
The consequences include unauthorized access to privileged commands, which can lead to system compromise and data breaches.
Yes, temporarily restricting the TZ environment variable for users with Sudo access can mitigate the risk until the patch is applied.
More information can be found on the CVE page for CVE-2026-96512, which provides detailed insights into the vulnerability and its implications.
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