CVE-2026-18508
Tar: tar: --one-top-level hardlink targets not confined to top-level directory enabling arbitrary file overwrite
02 Description
Tar: tar: --one-top-level hardlink targets not confined to top-level directory enabling arbitrary file overwrite
03 Exploitation and scoring
- Exploitation
- Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.
- SSVC decision
- ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
- AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
- Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.
- EPSS probability
- 0.14% probability of exploitation activity in the next 30 days.
- EPSS percentile
- Equal to or higher than the score of 3.3% of scored records. A rank, not a probability.
- NVD base score
- 4.4 (CVSS v3.x), scored by the NVD independently of the CNA.
- NVD CVSS vector
- CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N
- NVD analysis status
- Modified. NVD last modified this record on 2026-09-22.
- Red Hat severity
- Moderate. Red Hat's rating for its own products, not a CVSS rating.
Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.
04 Metadata
- Published
- 2026-08-03 14:51Z2 MO AGO
- Last updated
- 2026-09-22 21:29Z1 MO AGO
- Reserved
- 2026-07-31
- Assigning CNA
- redhat
- Record state
- PUBLISHED
- Severity
- Medium (CVSS 4.4)
- CNA CVSS vector
- CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N
- Weaknesses
- CWE-59Improper Link Resolution Before File Access ('Link Following')Base
- Data version
- 5.2
- Document digest
- 1f26bff3afd36dff65a3f98ccd88815fdd4905db52c3e5841b57821712808fc5
05 Affected products
06 References
- access.redhat.comRHSA-2026:50807https://access.redhat.com/errata/RHSA-2026:50807
- access.redhat.comRHSA-2026:61581https://access.redhat.com/errata/RHSA-2026:61581
- access.redhat.comRHSA-2026:61586https://access.redhat.com/errata/RHSA-2026:61586
- access.redhat.comRHSA-2026:61783https://access.redhat.com/errata/RHSA-2026:61783
- access.redhat.comRHSA-2026:66018https://access.redhat.com/errata/RHSA-2026:66018
- access.redhat.comRHSA-2026:70390https://access.redhat.com/errata/RHSA-2026:70390
- access.redhat.comhttps://access.redhat.com/security/cve/CVE-2026-18508
- bugzilla.redhat.comRHBZ#2509843https://bugzilla.redhat.com/show_bug.cgi?id=2509843
07 Fixed in
AlmaLinux 8
- tar Fixed in 2:1.30-13.el8_10
Source: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.
AlmaLinux 9
- tar Fixed in 2:1.34-13.el9_8
Source: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.
AlmaLinux 10
- tar Fixed in 2:1.35-13.el10_2
Source: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.
CloudLinux 8
- tar Fixed in 2:1.30-13.el8_10
Derived from AlmaLinux 8. Partial coverage: only packages taken from AlmaLinux 8 are listed.
Source: CloudLinux errata, CloudLinux Inc. Derived from: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.
CloudLinux 9
- tar Fixed in 2:1.34-13.el9_8
Derived from AlmaLinux 9. Partial coverage: only packages taken from AlmaLinux 9 are listed.
Source: CloudLinux errata, CloudLinux Inc. Derived from: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.
CloudLinux 10
- tar Fixed in 2:1.35-13.el10_2
Derived from AlmaLinux 10. Partial coverage: only packages taken from AlmaLinux 10 are listed.
Source: CloudLinux errata, CloudLinux Inc. Derived from: AlmaLinux, AlmaLinux OS. Copyright (c) 2023 AlmaLinux OS. Licensed under MIT License. Received through OSV.dev. Reformatted by exploit.cc.
Debian 12
- tar No fix yet
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Debian 13
- tar No fix yet
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Debian 14
- tar No fix yet
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 22.04 LTS
- tar No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 24.04 LTS
- tar No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 26.04 LTS
- tar No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu 26.10
- tar No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro 14.04 LTS
- tar No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro 16.04 LTS
- tar No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro 18.04 LTS
- tar No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
Ubuntu Pro 20.04 LTS
- tar No fix yet
Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.
A release or ecosystem missing from this list has no record here. It may be unaffected or not covered by the source. Source notices and licences.