CVE-2026-18508 (GCVE-0-2026-18508)
Vulnerability from cvelistv5 – Published: 2026-08-03 14:51 – Updated: 2026-09-10 17:23
VLAI
EPSS
VEX
Title
Tar: tar: --one-top-level hardlink targets not confined to top-level directory enabling arbitrary file overwrite
Summary
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.
Severity
4.4 (Medium)
SSVC
Exploitation: none
Automatable: no
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-08-03 16:02 UTC
CWE
- CWE-59 - Improper Link Resolution Before File Access ('Link Following')
Assigner
References
7 references
| URL | Tags |
|---|---|
| https://access.redhat.com/errata/RHSA-2026:50807 | vendor-advisoryx_refsource_REDHAT |
| https://access.redhat.com/errata/RHSA-2026:61581 | vendor-advisoryx_refsource_REDHAT |
| https://access.redhat.com/errata/RHSA-2026:61586 | vendor-advisoryx_refsource_REDHAT |
| https://access.redhat.com/errata/RHSA-2026:61783 | vendor-advisoryx_refsource_REDHAT |
| https://access.redhat.com/errata/RHSA-2026:66018 | vendor-advisoryx_refsource_REDHAT |
| https://access.redhat.com/security/cve/CVE-2026-18508 | vdb-entryx_refsource_REDHAT |
| https://bugzilla.redhat.com/show_bug.cgi?id=2509843 | issue-trackingx_refsource_REDHAT |
Impacted products
14 products
| Vendor | Product | Version | CPE status | |
|---|---|---|---|---|
| Red Hat | Red Hat Enterprise Linux 10 |
Unaffected:
2:1.35-13.el10_2 , < *
(rpm)
cpe:/o:redhat:enterprise_linux:10.2 |
||
| Red Hat | Red Hat Enterprise Linux 9 |
Unaffected:
2:1.34-13.el9_8 , < *
(rpm)
cpe:/o:redhat:enterprise_linux:9::baseos |
||
| Red Hat | Red Hat Discovery 2 |
Unaffected:
1788205779 , < *
(rpm)
cpe:/a:redhat:discovery:2::el9 |
||
| Red Hat | Red Hat Hardened Images |
Unaffected:
1.35-9.2.hum1 , < *
(rpm)
cpe:/a:redhat:hummingbird:1 |
||
| Red Hat | Red Hat Update Infrastructure 5 |
Unaffected:
1788880445 , < *
(rpm)
cpe:/a:redhat:rhui:5::el9 |
||
| Red Hat | Red Hat Update Infrastructure 5 |
Unaffected:
1788880464 , < *
(rpm)
cpe:/a:redhat:rhui:5::el9 |
||
| Red Hat | Red Hat Update Infrastructure 5 |
Unaffected:
1788880456 , < *
(rpm)
cpe:/a:redhat:rhui:5::el9 |
||
| Red Hat | Red Hat Update Infrastructure 5 |
Unaffected:
1788765051 , < *
(rpm)
cpe:/a:redhat:rhui:5::el9 |
||
| Red Hat | Red Hat Update Infrastructure 5 |
Unaffected:
1788880581 , < *
(rpm)
cpe:/a:redhat:rhui:5::el9 |
||
| Red Hat | Red Hat Enterprise Linux 6 |
cpe:/o:redhat:enterprise_linux:6
|
||
| Red Hat | Red Hat Enterprise Linux 7 |
cpe:/o:redhat:enterprise_linux:7
|
||
| Red Hat | Red Hat Enterprise Linux 8 |
cpe:/o:redhat:enterprise_linux:8
|
||
| Red Hat | Red Hat Hardened Images |
cpe:/a:redhat:hummingbird:1
|
||
| Red Hat | Red Hat OpenShift Container Platform 4 |
cpe:/a:redhat:openshift:4
|
Date Public
2026-07-31 00:00
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"datePublished": "2026-08-03T14:51:41.340Z",
"dateReserved": "2026-07-31T17:08:04.550Z",
"dateUpdated": "2026-09-10T17:23:39.917Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
}
}
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Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
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Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.
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