Privilege Escalation Vulnerability in libcap: Important Security Update Required
Summary
RLSA-2026:19130: Important: libcap security update. Affects libcap versions < 0:2.69-7.el10_1.1. Fixed in 0:2.69-7.el10_1.1. How to fix ↓
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Background
Libcap is a library designed for managing POSIX.1e capabilities, which allow fine-grained control over the privileges of processes in Unix-like operating systems. It enables applications to run with specific capabilities instead of full root access, enhancing security. However, a recent vulnerability has been identified that could allow attackers to exploit a race condition, leading to privilege escalation.
Vulnerability Detail
The vulnerability, identified as CVE-2026-4878, arises from a Time-of-Check to Time-of-Use (TOCTOU) race condition in the cap_set_file() function of libcap. This flaw allows an attacker to manipulate file capabilities during the check and use phases, potentially granting unauthorized privileges to a process. The ramifications of this vulnerability are significant, as it could lead to unauthorized access and control over system resources, compromising the integrity and confidentiality of the affected system.
How To Fix
Minimum fixed version
0:2.69-7.el10_1.1
This is the first release that contains the fix.
sudo dnf update libcapTip — Not sure which version your app runs? Vulert can match this fix to it. Scan free →
Workaround
As a temporary workaround, consider restricting access to the affected functionalities of libcap until the package can be updated. This may involve modifying permissions or using alternative methods to manage capabilities.
Conclusion
The identified vulnerability in libcap poses a significant risk of privilege escalation due to a TOCTOU race condition. It is essential to update the package to the fixed version to mitigate this risk. Users are encouraged to monitor their systems and apply the necessary updates promptly.
See every vulnerability recorded for libcap →
FAQ
CVE-2026-4878 is a security vulnerability in the libcap library that allows privilege escalation due to a TOCTOU race condition in the cap_set_file() function.
If exploited, this vulnerability can allow unauthorized users to gain elevated privileges, potentially compromising the security of your system.
If immediate updates are not possible, consider restricting access to functionalities that rely on libcap until a patch can be applied.
You can use Vulert, which monitors open-source vulnerabilities in your software. Simply upload your manifest file, such as package-lock.json, to check for vulnerabilities without needing to install any software.
The CVSS score for CVE-2026-4878 is 6.7, indicating a medium severity level that requires attention.
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