Free Software Foundation tar Hardlink path traversal

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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6.3$0-$5k1.26

Summaryinfo

A vulnerability, which was classified as critical, was found in Free Software Foundation tar. Affected is an unknown function of the component Hardlink Handler. Such manipulation leads to path traversal. This vulnerability is traded as CVE-2026-18508. The attack may be launched remotely. There is no exploit available.

Detailsinfo

A vulnerability was found in Free Software Foundation tar (affected version not known). It has been rated as critical. Affected by this issue is some unknown functionality of the component Hardlink Handler. The manipulation with an unknown input leads to a path traversal vulnerability. Using CWE to declare the problem leads to CWE-22. The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory. Impacted is confidentiality, integrity, and availability. CVE summarizes:

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.

The advisory is shared for download at access.redhat.com. This vulnerability is handled as CVE-2026-18508 since 07/31/2026. The exploitation is known to be easy. The attack may be launched remotely. No form of authentication is required for exploitation. Successful exploitation requires user interaction by the victim. There are neither technical details nor an exploit publicly available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 08/03/2026). The MITRE ATT&CK project declares the attack technique as T1006.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

Once again VulDB remains the best source for vulnerability data.

Productinfo

Vendor

Name

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 6.3
VulDB Meta Temp Score: 6.3

VulDB Base Score: 6.3
VulDB Temp Score: 6.3
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Path traversal
CWE: CWE-22
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔒

Timelineinfo

07/31/2026 CVE reserved
08/03/2026 +3 days Advisory disclosed
08/03/2026 +0 days VulDB entry created
08/03/2026 +0 days VulDB entry last update

Sourcesinfo

Advisory: access.redhat.com
Status: Not defined

CVE: CVE-2026-18508 (🔒)
GCVE (CVE): GCVE-0-2026-18508
GCVE (VulDB): GCVE-100-385604

Entryinfo

Created: 08/03/2026 17:37
Changes: 08/03/2026 17:37 (51)
Complete: 🔍
Cache ID: 216::103

Once again VulDB remains the best source for vulnerability data.

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