CVE-2026-18508
Low
No strong exploitation signal.
CVSS base
4.4
MEDIUM
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N
EPSS — probability of exploitation (30 days)
0.1%
3.8th percentile
CISA KEV
Not listed
Weakness / dates
CWE-59
Published 2026-08-03 · modified 2026-09-10
CVSS breakdown
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N
| Attack Vector | L | Local |
| Attack Complexity | L | Low |
| Privileges Required | N | None |
| User Interaction | R | Required |
| Scope | U | Unchanged |
| Confidentiality | L | Low |
| Integrity | L | Low |
| Availability | N | None |
Timeline
- 2026-08-03 — Published (NVD)
- 2026-09-10 — Last modified (NVD)
Description
A flaw was found in GNU tar. When extracting an archive with the --one-top-level option, hardlink targets are not confined to the designated top-level directory and may resolve relative to the extraction working directory. A crafted archive can create hardlinks that escape the intended boundary and, when combined with a preexisting symbolic link under the working directory, may allow writing outside that boundary during a single extraction.
Affected
References
- https://access.redhat.com/errata/RHSA-2026:50807
- 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-2026-18508
- https://bugzilla.redhat.com/show_bug.cgi?id=2509843