CVE-2026-18477
4.4 · MEDIUMOverview
CVE-2026-18477 is a medium-severity vulnerability affecting gnu tar. It was published on August 3, 2026 and has a CVSS 3.1 base score of 4.4 (MEDIUM).
This vulnerability has a CVSS 3.1 base score of 4.4, rated MEDIUM. It requires local or adjacent network access to exploit. Some level of privileges is required for exploitation.
Technical Description
A TOCTOU (Time-of-Check Time-of-Use) vulnerability in GNU tar's incremental dumpdir 'X' rename handling allows a local attacker with write access to a directory being backed up to influence the restore process if the attacker has access to the system where the restore is being performed. During restoration, files or directories may be created, renamed or overwritten outside the intended extraction directory. This could lead to unauthorized file modification or, in some cases, privilege escalation. Exploitation does not require the attacker to modify or craft the archive, and standard backup and restore workflows—including extracting into a newly created directory without using the -P option do not mitigate the issue.
Remediation
Check the references section for vendor advisories and patches from gnu. Update tar 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
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Frequently Asked Questions
What is CVE-2026-18477?
CVE-2026-18477 is a medium-severity vulnerability affecting gnu tar. It was published on August 3, 2026 and has a CVSS 3.1 base score of 4.4 (MEDIUM).
How severe is CVE-2026-18477?
This vulnerability has a CVSS 3.1 base score of 4.4, 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-2026-18477?
Check the references section for vendor advisories and patches from gnu. Update tar 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-2026-18477?
CyberStrike's AI-powered security agents can automatically detect CVE-2026-18477 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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