Time-of-check Time-of-use (TOCTOU) Affecting tar package, versions <2:1.30-13.el8_10


Severity

Recommended
0.0
medium
0
10

Based on AlmaLinux security rating.

Threat Intelligence

EPSS
0.08% (1st percentile)

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  • Snyk IDSNYK-ALMALINUX8-TAR-20075434
  • published24 Sept 2026
  • disclosed31 Aug 2026

Introduced: 31 Aug 2026

CVE-2026-18477  (opens in a new tab)
CWE-367  (opens in a new tab)

How to fix?

Upgrade AlmaLinux:8 tar to version 2:1.30-13.el8_10 or higher.
This issue was patched in ALSA-2026:70390.

NVD Description

Note: Versions mentioned in the description apply only to the upstream tar package and not the tar package as distributed by AlmaLinux. See How to fix? for AlmaLinux:8 relevant fixed versions and status.

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 Base Scores

version 3.1