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.
Published: 2026-08-03
Score: 4.4 Medium
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

Analysis and contextual insights are available on OpenCVE Cloud.

Remediation

Vendor Workaround

Do not perform incremental restores (-G/-g) from untrusted archives. Avoid restoring incremental backups on systems where untrusted users have shell access,​ perform restoration only on systems inaccessible to users.

Tracking

Sign in to view the affected projects.

Advisories

No advisories yet.

History

Thu, 13 Aug 2026 16:15:00 +0000

Type Values Removed Values Added
CPEs 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:10.0:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:*
cpe:2.3:o:redhat:enterprise_linux:9.0:*:*:*:*:*:*:*

Wed, 05 Aug 2026 10:45:00 +0000

Type Values Removed Values Added
First Time appeared Gnu
Gnu tar
Redhat hardened Images
Redhat openshift Container Platform
Vendors & Products Gnu
Gnu tar
Redhat hardened Images
Redhat openshift Container Platform

Wed, 05 Aug 2026 07:30:00 +0000

Type Values Removed Values Added
References

Tue, 04 Aug 2026 06:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Tue, 04 Aug 2026 00:15:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

threat_severity

Moderate


Mon, 03 Aug 2026 16:30:00 +0000

Type Values Removed Values Added
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.
Title Tar: tar: toctou in incremental dumpdir 'x' rename handling allows restore path escape
First Time appeared Redhat
Redhat enterprise Linux
Redhat hummingbird
Redhat openshift
Weaknesses CWE-367
CPEs cpe:/a:redhat:hummingbird:1
cpe:/a:redhat:openshift:4
cpe:/o:redhat:enterprise_linux:10
cpe:/o:redhat:enterprise_linux:6
cpe:/o:redhat:enterprise_linux:7
cpe:/o:redhat:enterprise_linux:8
cpe:/o:redhat:enterprise_linux:9
Vendors & Products Redhat
Redhat enterprise Linux
Redhat hummingbird
Redhat openshift
References
Metrics cvssV3_1

{'score': 4.4, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:N/I:H/A:N'}


Subscriptions

Gnu Tar
Redhat Enterprise Linux Hardened Images Hummingbird Openshift Openshift Container Platform
cve-icon MITRE

Status: PUBLISHED

Assigner: redhat

Published:

Updated: 2026-08-05T06:28:00.422Z

Reserved: 2026-07-31T10:48:40.556Z

Link: CVE-2026-18477

cve-icon Vulnrichment

Updated: 2026-08-03T16:25:26.068Z

cve-icon NVD

Status : Analyzed

Published: 2026-08-03T17:16:33.897

Modified: 2026-08-13T16:09:33.640

Link: CVE-2026-18477

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-07-31T00:00:00Z

Links: CVE-2026-18477 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-08-05T10:22:10Z

Weaknesses