Arbitrary file write via unsafe tar extraction
Published Aug 10, 2026 · Updated Aug 10, 2026
Path traversal in unearth 0.18.2 and earlier allows remote attackers to write files outside the extraction directory via crafted tar archives. In src/unearth/preparer.py, is_within_directory performs a lexical relative_to check without canonicalizing dot-dot segments, while _untar_archive extracts symlinks without validating their targets. Exploitation requires the process to fetch and unpack an attacker-controlled source distribution; writes are limited to locations accessible to that process.
Summary
What happened
Path traversal in unearth 0.18.2 and earlier allows remote attackers to write files outside the extraction directory via crafted tar archives. In src/unearth/preparer.py, is_within_directory performs a lexical relative_to check without canonicalizing dot-dot segments, while _untar_archive extracts symlinks without validating their targets. Exploitation requires the process to fetch and unpack an attacker-controlled source distribution; writes are limited to locations accessible to that process.
The record
- CVE
- CVE-2026-73030
- Published
- Aug 10, 2026
- Updated
- Aug 10, 2026
- Vendor
- Frost Ming
- Product
- unearth
- Classifications
- CWE-22, T1203
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Aug 10, 2026CVE publishedPublication date reported by the CVE source.
- Aug 10, 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?
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- Affected versionversion=0 <=0.18.2
What conditions does exploitation require?
What is affected?
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.
Weakness, pattern, technique
Public exploit references
- Tar-Slip in unearth sdist Extraction proof of conceptproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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