Arbitrary file writes via symlink path traversal
Published Jun 9, 2026 · Updated Jun 9, 2026
Symlink path traversal in Microsoft .NET 8, 9.0, and 10.0 allows local users to write arbitrary files outside a tar extraction directory. System.Formats.Tar's TarFile.ExtractToDirectory follows a crafted archive symlink and writes subsequent extracted content through it beyond the destination boundary. Exploitation requires local execution of an application that passes attacker-controlled tar content to the affected method; writes use that application's filesystem permissions.
Summary
What happened
Symlink path traversal in Microsoft .NET 8, 9.0, and 10.0 allows local users to write arbitrary files outside a tar extraction directory. System.Formats.Tar's TarFile.ExtractToDirectory follows a crafted archive symlink and writes subsequent extracted content through it beyond the destination boundary. Exploitation requires local execution of an application that passes attacker-controlled tar content to the affected method; writes use that application's filesystem permissions.
The record
- CVE
- CVE-2026-45491
- Published
- Jun 9, 2026
- Updated
- Jun 9, 2026
- Vendor
- Microsoft
- Product
- .NET 9.0
- Classifications
- CWE-59, T1565.001
- Attack vector
- local
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jun 9, 2026CVE publishedPublication date reported by the CVE source.
- Jun 9, 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?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=9.0.0 <9.0.17
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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