CVE-2026-27456
4.7 · MEDIUMOverview
CVE-2026-27456 is a medium-severity vulnerability affecting kernel util-linux. It was published on April 3, 2026 and has a CVSS 3.1 base score of 4.7 (MEDIUM).
This vulnerability has a CVSS 3.1 base score of 4.7, rated MEDIUM. It requires local or adjacent network access to exploit. Some level of privileges is required for exploitation.
Technical Description
util-linux is a random collection of Linux utilities. Prior to version 2.41.4, a TOCTOU (Time-of-Check-Time-of-Use) vulnerability has been identified in the SUID binary /usr/bin/mount from util-linux. The mount binary, when setting up loop devices, validates the source file path with user privileges via fork() + setuid() + realpath(), but subsequently re-canonicalizes and opens it with root privileges (euid=0) without verifying that the path has not been replaced between both operations. Neither O_NOFOLLOW, nor inode comparison, nor post-open fstat() are employed. This allows a local unprivileged user to replace the source file with a symlink pointing to any root-owned file or device during the race window, causing the SUID binary to open and mount it as root. Exploitation requires an /etc/fstab entry with user,loop options whose path points to a directory where the attacker has write permission, and that /usr/bin/mount has the SUID bit set (the default configuration on virtually all L
Remediation
Check the references section for vendor advisories and patches from kernel. Update util-linux to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
Affected Products
| Vendor | Product | Versions | Status |
|---|---|---|---|
| kernel | util-linux | >= 0, < 2.41.4 | Affected |
References
Frequently Asked Questions
What is CVE-2026-27456?
CVE-2026-27456 is a medium-severity vulnerability affecting kernel util-linux. It was published on April 3, 2026 and has a CVSS 3.1 base score of 4.7 (MEDIUM).
How severe is CVE-2026-27456?
This vulnerability has a CVSS 3.1 base score of 4.7, rated MEDIUM. It requires local or adjacent network access to exploit. Some level of privileges is required for exploitation.
How do I fix or remediate CVE-2026-27456?
Check the references section for vendor advisories and patches from kernel. Update util-linux to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2026-27456?
CyberStrike's AI-powered security agents can automatically detect CVE-2026-27456 across your infrastructure using autonomous pentesting, DAST scanning, and HackBrowser. The platform continuously monitors for known vulnerabilities and provides actionable remediation guidance prioritized by real-world exploitability.
How CyberStrike Helps
AI agents map your attack surface to find vulnerabilities like this one.
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