CVE-2026-18477

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.

CVSS v3 4.4 MEDIUM

4.4^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 0.8 / Impact : 3.6

Attack Vector LOCAL

Attack Complexity HIGH

Privileges Required LOW

User Interaction REQUIRED

Confidentiality Impact NONE

Integrity Impact HIGH

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://access.redhat.com/errata/RHSA-2026:49361	Vendor Advisory
https://access.redhat.com/errata/RHSA-2026:61581
https://access.redhat.com/errata/RHSA-2026:61586
https://access.redhat.com/errata/RHSA-2026:61783
https://access.redhat.com/errata/RHSA-2026:66018
https://access.redhat.com/security/cve/CVE-2026-18477	Vendor Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2509735	Issue Tracking Vendor Advisory

Configurations

Configuration 1 (hide)

OR	cpe:2.3:a:gnu:tar:1.35:::::::*
	cpe:2.3:a:redhat:openshift_container_platform:4.0:::::::*
	cpe:2.3:o:redhat:enterprise_linux:8.0:::::::*
	cpe:2.3:o:redhat:enterprise_linux:9.0:::::::*
	cpe:2.3:o:redhat:enterprise_linux:10.0:::::::*

History

No history.

Information

Published : 2026-08-03 17:16

Updated : 2026-09-10 18:17

NVD link : CVE-2026-18477

Mitre link : CVE-2026-18477

CVE.ORG link : CVE-2026-18477

JSON object : View

Products Affected

redhat

enterprise_linux
openshift_container_platform

gnu

tar

CWE

CWE-367

Time-of-check Time-of-use (TOCTOU) Race Condition

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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\u2014including extracting into a newly created directory without using the -P option do not mitigate the issue."}], "lastModified": "2026-09-10T18:17:56.970", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:a:gnu:tar:1.35:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "753D60F2-E001-49F6-A9B7-D8FCDE7E26BD"}, {"criteria": "cpe:2.3:a:redhat:openshift_container_platform:4.0:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "932D137F-528B-4526-9A89-CD59FA1AB0FE"}, {"criteria": "cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "F4CFF558-3C47-480D-A2F0-BABF26042943"}, {"criteria": "cpe:2.3:o:redhat:enterprise_linux:9.0:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "7F6FB57C-2BC7-487C-96DD-132683AEB35D"}, {"criteria": "cpe:2.3:o:redhat:enterprise_linux:10.0:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "D65C2163-CFC2-4ABB-8F4E-CB09CEBD006C"}], "operator": "OR"}]}], "sourceIdentifier": "secalert@redhat.com"}