Host file overwrite via unprotected cache symlink
Published Jun 25, 2026 · Updated Jun 25, 2026
Symlink following in Red Hat OpenShift Virtualization 4 allows local users to overwrite host files through a virt-launcher cache path. The virt-handler WriteToCachedFile function uses os.WriteFile and os.Chown on a launcher-rooted cache path without no-follow protection, so a planted symlink redirects both operations to a host file. Access to the virt-launcher container and a bridge or other non-masquerade interface are required; the write is limited to serialized JSON cache data, but the target file is also changed to UID 107.
Summary
What happened
Symlink following in Red Hat OpenShift Virtualization 4 allows local users to overwrite host files through a virt-launcher cache path. The virt-handler WriteToCachedFile function uses os.WriteFile and os.Chown on a launcher-rooted cache path without no-follow protection, so a planted symlink redirects both operations to a host file. Access to the virt-launcher container and a bridge or other non-masquerade interface are required; the write is limited to serialized JSON cache data, but the target file is also changed to UID 107.
The record
- CVE
- CVE-2026-13218
- Published
- Jun 25, 2026
- Updated
- Jun 25, 2026
- Vendor
- 389 Directory Server
- Product
- Red Hat OpenShift Virtualization
- Classifications
- CWE-61, T1611
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Jun 25, 2026CVE publishedPublication date reported by the CVE source.
- Jun 25, 2026Record updatedLatest update available in the CVE record.
Exploitability
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What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
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Public exploit references
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Technologies
Your stack
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Your stack
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