CVE-2026-18477: Tar: tar: toctou in incremental dumpdir 'x' rename handling allows restore

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.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

Red Hat Red Hat Enterprise Linux 10

Default version status: affected

2:1.35-13.el10_2 to < *unaffected

Red Hat Red Hat Enterprise Linux 8

Default version status: affected

2:1.30-13.el8_10 to < *unaffected

Red Hat Red Hat Enterprise Linux 9

Default version status: affected

2:1.34-13.el9_8 to < *unaffected

Red Hat Red Hat Discovery 2

Default version status: affected

1788205779 to < *unaffected

Red Hat Red Hat Hardened Images

Default version status: affected

1.35-9.1.hum1 to < *unaffected

Red Hat Red Hat Update Infrastructure 5

Default version status: affected

1788880445 to < *unaffected

Red Hat Red Hat Update Infrastructure 5

Default version status: affected

1788880464 to < *unaffected

Red Hat Red Hat Update Infrastructure 5

Default version status: affected

1788880456 to < *unaffected

Red Hat Red Hat Update Infrastructure 5

Default version status: affected

1788765051 to < *unaffected

Red Hat Red Hat Update Infrastructure 5

Default version status: affected

1788880581 to < *unaffected

Red Hat Red Hat Enterprise Linux 6

Default version status: unknown

Red Hat Red Hat Enterprise Linux 7

Default version status: unknown

Red Hat Red Hat Hardened Images

Default version status: unaffected

Red Hat Red Hat Hardened Images

Default version status: unaffected

Red Hat Red Hat Hardened Images

Default version status: unaffected

Red Hat Red Hat Hardened Images

Default version status: unaffected

Red Hat Red Hat Hardened Images

Default version status: unaffected

Red Hat Red Hat Hardened Images

Default version status: unaffected

Red Hat Red Hat Hardened Images

Default version status: unaffected

Red Hat Red Hat Hardened Images

Default version status: unaffected

Red Hat Red Hat Hardened Images

Default version status: unaffected

Red Hat Red Hat Hardened Images

Default version status: unaffected

Red Hat Red Hat OpenShift Container Platform 4

Default version status: affected

Red Hat Red Hat OpenShift Container Platform 4

Default version status: affected

CVE-2026-18477

Tar: tar: toctou in incremental dumpdir 'x' rename handling allows restore path escape

Description

Affected products

Red Hat Red Hat Enterprise Linux 10

Red Hat Red Hat Enterprise Linux 8

Red Hat Red Hat Enterprise Linux 9

Red Hat Red Hat Discovery 2

Red Hat Red Hat Hardened Images

Red Hat Red Hat Update Infrastructure 5

Red Hat Red Hat Update Infrastructure 5

Red Hat Red Hat Update Infrastructure 5

Red Hat Red Hat Update Infrastructure 5

Red Hat Red Hat Update Infrastructure 5

Red Hat Red Hat Enterprise Linux 6

Red Hat Red Hat Enterprise Linux 7

Red Hat Red Hat Hardened Images

Red Hat Red Hat Hardened Images

Red Hat Red Hat Hardened Images

Red Hat Red Hat Hardened Images

Red Hat Red Hat Hardened Images

Red Hat Red Hat Hardened Images

Red Hat Red Hat Hardened Images

Red Hat Red Hat Hardened Images

Red Hat Red Hat Hardened Images

Red Hat Red Hat Hardened Images

Red Hat Red Hat OpenShift Container Platform 4

Red Hat Red Hat OpenShift Container Platform 4

References