Tar: tar: toctou in incremental dumpdir 'x' rename handling allows restore path escape
Historical advisory recorded 30 Oct 2026 19:45:26 UTC. Read the latest advisory.
cve-program · CVE-2026-18477
PublishedA 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.
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cve-program · CVE-2026-18477
PublishedTar: tar: toctou in incremental dumpdir 'x' rename handling allows restore path escape
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.
- Source published
- 3 Aug 2026 15:34:36 UTC
- Source modified
- 30 Oct 2026 18:49:29 UTC
- Saved here
- 30 Oct 2026 19:45:26 UTC
- Source terms
- CVE Program Terms of Use
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Source: cve-program · CVE Program Terms of Use. The publisher's wording is preserved. ChangeIntel groups the information and labels changes. The JSON record includes additional source fields.
CVSS 3.1 · 4.4 CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:N/I:H/A:N