CVE-2026-18508

File overwrite via unconfined hardlink targets

Published Aug 3, 2026 · Updated Aug 3, 2026

Path traversal in GNU tar on affected Red Hat products allows local users to overwrite files by extracting a crafted archive. With --one-top-level, hardlink targets resolve from the extraction working directory instead of remaining beneath the designated top-level directory, and a preexisting symlink can bypass normal path protections. Exploitation requires user interaction to extract an untrusted archive with that option from a working directory containing a suitable symlink; default extraction is unaffected.

CVSS severity4.4
Medium
EPSS probability0.14%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Path traversal in GNU tar on affected Red Hat products allows local users to overwrite files by extracting a crafted archive. With --one-top-level, hardlink targets resolve from the extraction working directory instead of remaining beneath the designated top-level directory, and a preexisting symlink can bypass normal path protections. Exploitation requires user interaction to extract an untrusted archive with that option from a working directory containing a suitable symlink; default extraction is unaffected.

The record

CVE
CVE-2026-18508
Published
Aug 3, 2026
Updated
Aug 3, 2026
Vendor
389 Directory Server
Product
Red Hat Enterprise Linux 10
Classifications
CWE-59, T1204.002
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 3, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected versions are unavailable in this record. Check the vendor advisory for version and patch details.

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

389 Directory Server · Red Hat Enterprise Linux 10Affected versions are unavailable in this record.
389 Directory Server · Red Hat Hardened ImagesAffected versions are unavailable in this record.
389 Directory Server · Red Hat Enterprise Linux 9Affected versions are unavailable in this record.
389 Directory Server · Red Hat OpenShift Container Platform 4Affected versions are unavailable in this record.
389 Directory Server · Red Hat Enterprise Linux 8Affected versions are unavailable in this record.

Published CVSS scores

4.4Red HatCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-59Improper Link Resolution Before File Access ('Link Following')
T1204.002User Execution: Malicious File

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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